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C    O    M    P    E    h 

J?  OF 

LOGICK  : 

FOR    THE    USE    OF    THE 

U  N  I  V  E   R    SIT* 

O  V 

PENNSYLVANIA. 

By  JOHN  ANDREWS,  D.  D. 
Vice  Provost  of  the  University. 


PHILADELPHIA : 

PRINTED     BY     BUDD    AND    BARTRAM, 

FOR  THOMAS  DOBSON,  AT  THE  STONE  HOUSE, 
NO.    41,    SOUTH    SECOND    STREET. 

l80I. 


PREFACE. 


KJ¥  the  few  treatifes  of  Logick 
which  the  author  of  the  following 
compilation  has  perufed,  Duncan's 
has  always  appeared  to  him  to  be 
the  befl.  But  this  treatife,  however 
excellent,  is  for  the  mod  part  too 
diffufive,  and  in  fome  places,  per- 
haps, even  too  fcientifick,  for  the 
ufe  of  young  beginners ;  at  the  fame 
time  that  it  omits  a  number  of  par- 
ticulars, of  which  (as  they  are  gene- 
rally 


PREFACE, 
rally  taught  in  the  fchools,  and  oc- 
cafionally  alluded  to  in  converfation 
as  well  as  books)  a  teacher  would 
not  wilh  his  pupils  to  be  wholly  ig- 
norant. To  obviate  thefe  objections, 
and  yet  retain  as  much  as  poffible 
the  features  of  Duncan,  is  the  aim 
of  the  prefent  Compend  ;  which  was 
compofed  fome  years  ago,  and  is  now 
printed  that  the  claries,  for  whofe  ufe 
it  was  intended,  may  no  longer  have 
the  trouble  of  tranfcribing  it. 


A 

C   O    M    P    E    N    D 


OF 


LOGICK. 


-LOGICK  is  that  fcience  which  explains 
the  operations  of  the  human  undemand- 
ing, in  acquiring  and  communicating 
knowledge.  And  as  thefe  have  been 
ufually  ftated  to  be  four, — apprehend- 
ing, JUDGING,  REASONING,  and  AR- 
RANGING our  thoughts  in  a  fuitable 
manner ;  fo  Logick,  which  treats  of 
thefe  operations,  is  ufually  divided  into 
four  parts. 

B  P  \ 


(      io     ) 
PART     I. 

Of  Simple  Apprehenfion. 

Simple  apprehenfion  being  that  ope- 
ration of.  the  mind  by  which  it  is  furnifh- 
cd  with  ideas,  a  treatife  on  it,  is,  in  a 
great  meafure,  a  treatife  on  ideas,  and 
on  the  procedure  of  the  mind  with  re- 
fpecr  to  them  :  and  it  is  alfo  a  treatife  on 
words  and  definitions ;  becaufe,  without 
thefe,  we  fliould  often  be  at  a  lofs  both 
in  acquiring  and  communicating  our  ideas. 
The  firfl:  part,  therefore,  of  Logick,  may 
be  divided  into  two  chapters  :  One  treat- 
ing of  ideas ;  and  the  other,  of  terms 
and  definitions. 


CHAP. 


(  «  ) 


CHAP.     1. 


Of  Simple  Apprehenfion,  and  the  faculties 
by  which  it  is  exerted : — Of  Ideas,  or 
the  first  principles  of  Knowledge  : — Of 
the  fources  from  which  they  are  derived  ; 
and  of  the  different  forts  of  them. 

Simple  Apprehension  is  that  ope- 
ration of  the  underftanding  by  which  it 
attends  to,  and  notices,  the  fevcral  ob- 
jects that  are  prefented  to  it.  It  is  cal- 
led fimple  apprehenfion,  becaufe  it  is  em- 
ployed in  the  mere  apprehending  or  no- 
ticing of  things  :  without  comparing 
them  with  each  other,  or  aligning  to 
them  any  attributes ;  which  is  the  pro- 
vince of  judgment.  And  by  this  operation 
it  is,  that  the  mind,  as  we  have  already 
obferved,    is    furniihed    with   ideas :  for 

without 


(       M       ) 

without  previoufly  attending  to,  and  no- 
ticing, the  objects  that  are  prefented  to 
it,  it  is  impoffible  that  the  mind  fhould 
ever  have  any  ideas  of  them ;  or,  in 
other  words,  be  able  to  reprefent  to  it- 
felf  the  appearances  which  they  ex- 
hibit. 

In  performing  this  operation,  two  facul- 
ties are  made  ufe  of,  which  are  quite 
diftinct  from  each  other ;  sensation, 
and  consciousness.  If  the  object  oc- 
curring be  an  external  thing,  the  mind 
perceives  it,  and  its  qualities,  by  means 
of  the  fenfes  ;  and  the  power  of  doing 
this  is  called  the  faculty  of  sensa- 
tion :  if  it  be  an  internal  thing,  that  is,  if 
it  be  any  operation  or  emotion  of  the  mind, 
the  mind  attends  to  and  notices  it,  with- 
out making  ufe,  fo  far  as  we  know,  of 
any  bodily  organ ;  and  it  is  this  power, 

which 


I 


(    ft    ) 

which  we  call  the  faculty  of  con- 
sciousness. 

The  term  idea  is  derived  from  the 
Greek  word  e</£,  I  fee  ;  and  by  ideas  are 
meant,  the  views  which  the  mind  takes 
of  things,  when  they  are  no  longer  pre- 
fent.  In  the  language  of  the  fchools, 
ideas  are  the  types  or  refemblances  of 
things  ;  and  things  themfelves  are  the 
archetypes,  or  originals  of  which  the 
refemblances  are  made.  When  an  ex- 
ternal object  is  prefent,  and  attended  to 
by  my  mind,  I  am  faid  to  perceive  it; 
and  when  my  mind  is  engaged  in  any 
operation,  or  agitated  by  any  paflion  or 
emotion,  I  am  faid  to  be  conscious  of 
that  operation,  or  of  that  paflion  or 
emotion :  but  when  the  external  object 
is  no  longer  prefent,  fo  as  to  affect  the 
organs  of  fenfe, — or  when  the  operation 
which  had  engaged  my  mind  has  ceafed 

to 


C     H     ) 

to  engage  it,  or  the  pafiion  or  emotion, 
by  which  I  was  agitated,  now  agitates 
me  no  more, — I  am  capable  of  thinking 
of  the  object  which  1  before  perceived, 
or  of  the  operation  or  emotion  of  which 
I  was  confcious,  and  of  reprefenting  to 
myfelf  the  appearances  which  they  re- 
fpe&ively  exhibited ;  and  when  I  do  fo, 
I  am  faid  to  have  ideas  of  them. 

It  has  been  flated,  that  all  external 
things  and  their  qualities  are  noticed  by 
means  of  the  fenfes ;  and  internal  things, 
that  is,  the  operations  and  emotions  of 
the  mind,  by  confcioufnefs :  now  all 
the  objects  of  which  we  have  any  know- 
ledge, are  either  external  things  and 
their  qualities,  or  the  operations  and 
emotions  of  the  mind  :  and,  confequent- 
Jy,  all  our  ideas,  how  numerous  foeyer 
they  may  be,  are  derived  from  thefe  two 
fources. 

As- 


(     15     ) 

As  ideas  are  the  firfl  elements  of  all 
our"  knowledge  ;  fo  fenfation  and  con- 
fcioufnefs  are  the  firft  of  our  intellectual 
faculties  which  are  exerted  by  us.  And, 
again,  we  can  have  no  ideas  of  the  opera- 
tions of  our  own  minds  until  they  are 
exerted ;  nor  can  they  be  exerted,  he- 
fore  the  mind  is  furnifhed  with  ideas, 
about  which  to  employ  them :  •  but 
the  ideas  which  give  the  firft  employ- 
ment to  our  faculties,  are  evidently  the 
ideas  of  external  things,  communicated  by 
the  fenfes :  whence  it  is  plain,  that  all  our 
knowledge  mufl  begin  in  fenfation ;  and 
that  the  operation  of  this  faculty  is  prior 
even  to  that  of  confeioufnefs. 

Ideas  are  either  simple  or  complex. 
A  fimple  idea  is  an  idea  of  a  fimple  object ; 
that  is,  of  an  object  without  parts :  or  it 
may  be  defined,  an  idea  which  cannot 
be  refolved  into  two  or  more  ideas.     A 


(       x6      ) 

complex  idea  is  an  idea  of  a  complex 
object ;  that  is,  of  an  object  that  confifts 
of  parts :  or,  it  is  an  idea,  that  may  be 
refolved  into  two  or  more  ideas. 

To  the  former  of  thefe  claffes  belong 
all  our  ideas  of  qualities,  and  of  the 
operations  and  emotions  of  our  own 
minds.  The  qualities  of  external  things 
are  called  sensible  qualities  ;  and 
may  be  reduced  to  five  general  heads, 
according  to  the  feveral  fenfes  which  are 
affected  by  them.  Light  and  colours 
are  perceived  by  the  eye  ;  founds,  by  the 
ear;  taftes,  by  the  tongue;  fmells,  by 
the  nofe  ;  and  heat  and  cold,  roughnefs 
and  fmoothnefs,  hardnefs  and  foftnefs, 
&c,  by  the  touch.  Extenfion,  figure, 
reft,  and  motion,  we  perceive  by  two 
fenfes  ;  feeing,  and  feeling.  To  which 
may  be  added,  that  our  ideas  of  pleafure 
and  pain,    of  power,    exiftence,    unity, 

and 


(     *7    ) 

and  fuccefllon,  are  conveyed  into  our  un- 
derstandings both  by  fenfation  and  con- 
fcioufnefs  ;  that  is,  both  by  the  action  of 
objects  around  us,  and  the  confcioufnefs 
of  what  we  feel  within. 

To  this  general  view  of  our  fimple 
ideas  may  be  fubjoined  the  two  follow- 
ing obfervations.  The  first  is,  that  fim- 
ple ideas  can  only  be  conveyed  into  the 
mind  by  the  proper  channels  and  avenues 
provided  by  nature ;  infomuch  that  if 
we  are  deflitute  of  any  of  thofe  inlets, 
all  the  ideas,  thence  arifing,  are  abfo- 
lutely  loft  to  us ;  nor  can  we,  by  any 
quicknefs  of  underftanding,  find  a  remedy 
for  this  want.  A  man  born  blind  is  in- 
capable of  ideas  of  light  and  colours  \ 
as  one,  who  is  born  deaf,  can  form  no 
conception  of  founds.  And  hence  it  ap- 
pears, that  thefe  our  fimple  ideas  are 
iufl  fuch  as  nature  furmlhes  them,  and 


i,-. 


(     i8     ) 

have  no  dependence  on  our  will :  we  can 
neither  deftroy  them  when  in  the  under- 
standing ;  nor  fafhion  or  invent  any  new 
one,  not  taken  in  by  the  ordinary  means 
of  apprehennon.  So  that  the  utmoft 
bounds  of  human  knowledge  cannot  ex- 
ceed the  limits  of  our  fimple  ideas  and 
their  various  combinations.  The  fecond 
is,  that  though  the  mind,  in  multiplying 
its  conceptions,  can  avail  itfelf  of  no 
other  materials  than  thofe  which  are  fur- 
niflied  by  fenfation  and  confeioufnefs ; 
vet,  as  it  has  a  power  of  combining 
thefe  materials  in  a  great  variety  of 
ways,  it  finds  itfelf  in  poiTeiTion  of  an 
inexhauftible  treafure  of  ideas,  fufficient 
to  employ  it  to  the  full  extent  of  its 
powers. 

Complex  ideas  are  of two  forts  :  those 

WHICH  ARE  CONVEYED  INTO  THE  MIND 
BY  THINGS    REALLY    EXISTING    IN   NA- 
TURE 'y 


(     19     ) 

ture  ;  and   those  which  are    the 

WORKMANSHIP  OF  THE  MIND  ITSELF. 

Things  really  exifting  in  nature  are  all 
comprifed  under  the  general  name  of 
substances  ;  which  are  either  material 
or  immaterial.  And  the  ufual  definition 
of  a  fubftance  is,  that  it  is  a  thing  which 
fubfifts  of  itfelf,  without  dependence 
upon  any  created  being,  and  is  the  fub- 
ject  of  modes.  The  idea,  for  example, 
of  a  material  fubftance  includes  in  it  the 
idea  of  a  thing  fubfiiling  of  itfelf ;  and  the 
ideas  of  its  qualities,  by  which  only,  as 
we  find  by  experience,  it  is  made  known 
to  us :  the  idea  of  an  immaterial  fub- 
ftance, in  like  manner,  includes  the  idea 
of  a  thing  fubfifting  of  itfelf;  and  the 
ideas  of  its  operations,  by  which  only, 
as  we  alfo  find  by  experience,  it  is  made 
known  to  us.  Whence  it  appears,  that, 
whether  the  fubftance  be  material  or  im- 
material, 


C       20      ) 

material,  the  thing  itfelf  is  unknown  to 
us ;  and  that  they  are  the  qualities  only 
of  bodies,  and  the  operations  of  mind, — 
or,  in  other  words,  the  modes  only  or 
attributes  of  things, — with  which  we  are 
acquainted. 

Modes  are  divided  into  essential 
and  accidental.  An  eflential  mode 
is  that  which  cannot  be  feparated  from 
its  fubjecl:,  without  deftroying  the  na- 
ture of  the  fubjecl: :  an  accidental  mode 
is  that  which  may  be  feparated  from  its 
fubjecl:,  and  the  nature  of  its  fubjecl:  re- 
main the  fame  as  it  was  before.  Round- 
nefs,  for  example,  is  an  effential  mode 
of  a  bowl ;  becaufe  a  thing  cannot  be  a 
bowl  without  being  round  :  but  any  par- 
ticular colour  is  an  accidental  mode  of  a 
bowl  j  becaufe  if  a  bowl,  or  a  ball,  which 
is  now  blue,  were  to  be  painted  white,  it 
would  flill  be  a  bowl  as  much  as  ever. 

Effential 


(   jm    ) 

Effential  modes  are  divided  into  pri- 
mary and  secondary.  A  primary  ef- 
fential  mode  is  that  which  is  derived 
from  no  other  mode,  and  conftitutes  a 
thing  what  it  is.  A  fecondary  effential 
mode  is  that,  which,  although  infepa- 
rable  from  its  fubjecl:,  is  derived  from 
fome  other  mode.  Thus  roundnefs  is  a 
primary  effential  mode  of  a  bowl ;  be- 
caufe  we  do  not  conceive  of  it  as  derived 
from  any  other  quality  of  a  bowl :  but 
volubility,  or  aptnefs  to  roll,  is  a  fecon- 
dary effential  mode  of  a  bowl ;  becaufe 
it  arifes  from  another  quality  of  it,  that 
is,  its  roundnefs.  The  primary  effential 
mode  has  been  called  differentia, or  the 
difference ;  the  fecondary  effential  mode, 
proprium,  or  a  property  ;  and  the  acci- 
dental mode,  accidens. 

Complex  ideas   which  are    the  work- 
manfhip  of  the  mind  are  divided  into  com- 
pound,— 


(       22      ) 

POUND, UNIVERSAL, GENERAL,  Or  AB- 
STRACT,— and  RELATIVE. 

Compound  ideas  are  thofe,  which  the 
mind  forms  by  putting  two  or  more 
ideas  together.  Thefe  combinations  are 
fometimes  made  by  adding  they^^  idea 
to  itfelf:  thus,  by  adding  the  idea  of 
unity  to  itfelf  repeatedly,  and  retaining 
the  feveral  amounts  in  our  minds,  we 
come  by  all  the  different  combinations  of 
numbers :  in  the  fame  way  are  formed 
the  different  ideas  of  yards,  perches,  fur- 
longs, miles,  leagues,  &c.  ;  alfo  thofe 
of  weeks,  months,  years,  &c.  But, 
more  frequently,  our  compound  ideas 
are  formed  by  combining  ideas  of  a  dif- 
ferent kind  together.  The  compofer  of 
mufick,  for  example,  forms  the  idea  of  a 
tune  which  he  is  compofmg, — and  the 
mechanick,  the  idea  of  a  machine  which 
lie  is  projecting, — -by  bringing  together, 

in 


(     23     ) 

in  the  former  cafe,  a  number  of  notes— 
and,  in  the  latter,  of  parts, — that  are  dif- 
ferent from  each  other. 

An  abflracl:,  univerfal,  or,  as  it  is 
more  commonly  called,  a  general  idea, 
is  an  idea  that  will  apply  to  feveral 
individuals,  or  to  feveral  clafTes  of  in- 
dividuals. If  it  apply  to  individuals  only, 
the  clafs,  which  correfponds  to  it,  and 
comprehends  individuals,  is  termed  a 
species  ;  if  to  feveral  clafTes  of  indivi- 
duals, the  clafs  which  correfponds  to  it, 
and  comprehends  thefe  feveral  clafTes  of 
individuals,  is  termed  a  genus.  The 
formation  of  thefe  ideas  depends  on  a 
power  which  the  mind  pofTcfTes  of  re- 
moving, from  its  idea  of  any  object, 
what  .is  peculiar  to  that  object ;  from  its 
idea  of  an  individual,  whatever  is  pecu- 
liar to  that  individual ;  and  from  its  ideas 
of  a  fpecies,  whatever  is  peculiar  to  that 

fpecies : 


(     *4     ) 

fpecies :  a  power,  which,  by  the  writ- 
ers on  the  human  mind,  is  called  the 

FACULTY      OF      ABSTRACTION.  And 

hence  it  appears,  that  it  is  not  without 
reafon,  that  our  general  ideas  are  ranked 
among  thofe  which  are  the  workmanihip 
of  the  mind,  and  have  nothing  in  nature 
to  which  they  correfpond. 

But  that  this  may  be  better  under- 
ftood,  it  will  be  worth  while  to  take  a 
more  diftincl:  view  of  the  procefs  of  the 
underftanding  in  the  formation  of  thefe 
ideas.  All  the  things  in  nature  are  in- 
dividual things :  that  is,  every  thing  is 
itfelf,  and  one ;  and  not  another,  and 
more  than  one.  .  But  when  we  come  to 
take  a  view  of  the  feveral  individuals, 
and  obferve  that  a  number  of  them  re- 
femble  each  other  in  one  or  more  par- 
ticulars of  importance,  felecting  the  par- 
ticulars in  which  they  agree,  and  remov- 


•      (       2J       ) 

ing  all  thofe  in  which  they  disagree,  we 
frame  to  ourfelves  a  general  idea  appli- 
cable to  ftveral  individuals  ;  that  is,  to 
a  particular  fpecies.  Thus  certain  ani- 
mals being  found  to  refemble  each  other 
in  having  an  erect  form,  and  in  being 
endowed  with  the  faculties  of  reafon  and 
fpeech,  we  take  thefe  important  particu- 
lars which  are  common  to  thein  all,  and 
excluding  what  is  peculiar  to  each,  we 
form  a  general  idea,  to  which  we  give 
the  name  of  man  ;  and  this  name  belongs 
equally  to  every  individual  who  is  pof- 
feffed  of  the  form  and  faculties  above 
mentioned.  This  is  the  firft  flep  or  gra- 
dation in  the  forming  of  abftract  ideas, 
when  the  mind  confines  itfelf  to  the  con- 
sideration of  individuals,  and  frames  an 
idea  th.Lt  comprehends  fuch  only  under  it. 
Again  :  having  ranged  things  into  fpe- 
cies, according  to  the  refeniblance  fcv.nd 
D  ar 


(    26    ; 

among  them,  we  begin  to  compare  the 
ieveral  fpecies  with  each  other ;  and 
often  obferve,  in  thefe  alfo,  a  refem- 
blance,  in  one  or  more  particulars  of  im- 
portance. Upon  this,  throwing  out  all 
the  particulars  in  which  they  difagree, 
and  retaining  thofe  only,  in  which  there 
is  a  refemblance,  we  frame  a  ftill  more 
general  idea,  comprehending  under  it 
Ieveral  fpecies.  Thus,  a  fparrow,  a  hawk, 
an  eagle,  &c. ,  are  diftincl  fpecies  of  birds : 
They  neverthelefs  refemble  each  other 
in  being  covered  with  feathers,  and  pro- 
vided with  wings  which  bear  them  through 
the  air :  Out  of  thefe  particulars  we 
form  a  new  idea,  and  appropriating  to  it 
the  name  bird,  mark  by  that  word  a 
higher  clafs,  which  comprehends  in  it  all 
the  former.  This  higher  clafs,  which 
extends  to  feveral  fpecies  of  things,  is 
called  a  genus  ;  and  is  the  fecond  flep 

which 


(     27     ) 

which  the  mind  takes  in  the  formation  of 
it's  general  ideas. 

But,  in  rifing  from  particulars  to  ge- 
nerals, the  mind  does  not  confine  itfelf  to 
one  or  two  gradations.  For  when  wc 
have  reduced  things  into  fpecies,  and 
thefe  again  into  genera,  thefe  genera  are 
often  found  to  refemble  each  other  in 
fome  particulars,  which  being  combined 
together  into  one  idea  includes  a  new  and 
more  comprehenfive  clafs  of  things.  Thin 
bird  is  a  genus,  comprehending  the  fe- 
veral  fpecies  of  fparrow,  hawk,  eagle, 
&c. :  fifh  is  a  genus,  including  the  feveral 
fpecies  of  living  creatures  which  inhabit 
the  waters,  as  dolphins,  fturgeons,  &c.  : 
beafl  or  quadruped,  and  infect,  are  alfo 
genera,  which  extend  to  many  fpecies  : 
yet  all  thefe  different  genera  have  this  in 
common,  that  they  are  provided  with 
organical  bodies  fitted  for  the  purpofes  of 

life 


(       28       ) 

life  and  fpontaneous  motion.  An  idea, 
therefore,  made  up  of  thefe  particulars 
only,  will  comprehend  all  the  genera 
above  mentioned  ;  and  the  word,  animal, 
by  which  it  is  expreffed,  becomes  a  ge- 
neral name  for  the  feveral  creatures  en- 
dued with  life,  fenfe,  and  fpontaneous 
motion. 

Further :  all  things,  animate  and  in- 
animate, refemble  each  other  in  this  ref- 
pecl:,  that  they  are  created  ;  whence  we 
refer  them  to  a  genus  (till  higher,  which 
'may  be  called  creature:  a  name,  which 
belongs  equally  to  every  genus  and  fpecies 
of  created  things,  and  to  each  individual 
thing  that  is  created. 

And  further  dill :  all  things,  what- 
ever, exift,  or  are ;  and  in  this  refpecl: 
aue  faid  to  refemble  each  other  :  in  which 
view  we  refer  them  to  a  genus  flill  higher, 

called 


(     =9     ) 

called  Being  9  which  is  the  higheft  poflible 
genus. 

In  a  feries  of  genera,  riling  in  this 
manner  one  above  another,  each  fuccef- 
five   genus  is   called,  in    the   fchools,  a 

GENUS  GENERALIUS,  Or  HIGHER  GENUS; 

and  the  genus  by  which  each  feries  is 
terminated,  they  diflinguifh  by  the  name 

Of    GENUS     GENERALISSIMUM.       In    like 

manner,  the  feveral  genera,  comprehend- 
ed under  a  higher  genus,  are,  in  refpect 
to  it,  confidered  as  fpecies ;  and  as  thefe 
have  alfo  fpecies  under  them,  the  inferior 
divifions  are,  for  the  fake  of  diftin&ion, 
termed  species  specialiores,  or  low- 
er species.  And  the  lowefl:  fubdivifions 
of  all,  comprehending  only  individuals, 
(which,  as  has  been  already  mentioned, 
conftitute  the  proper  fpecies)  are,  in  ref- 
pec"r.  to  the  feries,  denominated  the 
species  specialissim^e.      All  that  lie 

between 


(    3°     ) 
between  thefe  and  the  higheft  diftribution 
of  things,  or  genus  general  illinium,  are 

the  INTERMEDIATE  GENERA  AND  SPE- 
CIES ;  which  are  termed  fucceffively  genus 
generalius,  or  fpecies  fpecialior,  accord- 
ing as  we  conflder  them  in  the  afcending, 
or  defcending,  feries  of  our  ideas ;  or,  to 
fpeak  in  the  language  of  logicians,  accord- 
ing to  their  afcent,  ;  or  defcent,  in  the 
line  a  pradicamentali. 

And  here  we  may  take  occafion  to 
mention  merely,  that,  by  the  ancient 
writers  of  logick,  a  genus  general  illinium, 
with  all  its  divifions  and  fubdivifions,  was 
termed  a  category,  or  predica- 
ment. And  as  Ariflotle  fancied,  that 
all  the  things  in  nature  might  be  reduced 
to  ten  general  heads,  or  clalfes,  namely, 
fub  stance,  quantity,  quality,  relation,  ac- 
tion,  pajfion,    place,    time,  fituation,  and 

cloathing  ; 


(    3i     ) 

cloathing ;  thefe   have  been   called  the 

TEN   CATEGORIES. 

It  is  of  more  importance  to  remark, 
that,  though  many  of  our  general  ideas 
are  evidently  combinations  of  different 
fimple  ideas,  and  in  that  view  of  them 
are  included  in  the  clafs  of  compound 
ideas,  we  are  carefully  to  diftinguifh 
between  an  idea  as  it  is  compound,  and 
as  it  is  general  or  univerfal. 

An  idea  is  termed  compound,  with 
refpect  to  the  feveral  ideas  which  are 
combined  in  it ;  general  or  univerfal, 
with  refpecl:  to  the  individuals,  fpecies, 
or  genera,  to  which  it  extends.  Thus  the 
idea  of  a  bird,  confidered  as  a  compound 
idea,  includes  life,  fenfe,  fpontaneous 
motion,  a  covering  of  wings,  feathers, 
&c. :  but,  as  a  general  idea,  it  denotes 
the  feveral  fpecies  of  the  feathered  crea- 
tion, the  hawk,  the  eagle,  the  lark,  &o; 

to 


(      32      ) 

to  air  which  it  extends  with  equal  pro- 
priety. In  the  former  cafe,  the  feveral 
parts  of  the  compound  idea  are  called  its 
comprehension;  in  the- latter,  the 
genera,  the  fpecies,  and  the  individuals, 
to  which  the  univerfal  idea  may  be  ap- 
plied, are  called  its  extension. 

The  third  and  lad  divifion,  of  thofe 
complex  ideas  which  are  the  workman- 
ship of  the  mind,  confifts  of  our  relative 
ideas.  A  relative  idea,  is  an  idea  which 
arifes  from  the  comparing  of  things,  one  . 
with  another.  For  the  mind  is  not  limit- 
ed to  the  confideration  of  objects,  as  they 
are  in  themfelves  merely ;  but  can  ex- 
amine them  as  connected  with  other  things 
brought  into  view  at  the  fame  time.  And 
when  it  does  fo,  and  thence  acquires  new 
ideas,  the  ideas  thus  acquired  are  called 
relative  ideas ;  and  make,  as  is  fuppofed, 
the  largeft  clafs  of  our  ideas.     For  every 

fmgle 


(    33    ) 

fingle  objeft  will  admit  of  almofl:  innume- 
rable companions  with  others,  and,  in 
this  way,  may  become  a  very  plentiful 
fource  of  ideas  to  the  undemanding. 
Thus,  if  we  compare  one  thing  with 
another  in  refpect  to  bulk,  we  get  the 
idea  of  greater  and  lefs,  or  of  equality  : 
if,  in  refpect  of  time,  of  older  and 
younger :  and  fo  of  other  relations,  which 
we  can  purfue  at  pleafure,  and  almofl 
without  end. 

So  much,  with  refpecl  to  ideas;  which 
are  the  fubject  of  the  firfh  chapter.  We 
have  Mated,  that  all  our  fimple  ideas  arc 
conveyed  into  the  underftanding  either 
by  fenfation  or  confeioufnefs ;  and  are 
the  materials  out  of  which  all  others  are 
formed:  that  the  mind,  though  it  has 
no  power  over  thefe,  either  to  fafhion 
or  to  deftroy  them,  can  yet  combine  them  - 
in  an  infinite  number  of  ways ;  and  that 
E  from 


(     34     ) 

from  their  various  combinations  refult  all 
our  complex  ideas :  that  thefe  complex 
ideas  are  of  two  principal  kinds ;  firft, 
fuch  as  are  derived  from  without,  andre- 
prefent  thofe  combinations  of  fimple  ideas 
that  have  a  real  exiflence  in  nature, — 
of  which  fort  are  all  our  ideas  of  fub- 
flances  ;  fecondly,  fuch  as  are  formed  by 
the  mind  itfelf,  arbitrarily  uniting  and 
putting  together  its  ideas :  and  that,  as 
thefe  lad  make  by  far  the  largeft  clafs, 
and  comprehend  all  thofe  ideas  which 
may  be  properly  termed  our  own,  as 
being  the  workmanfhip  of  the  under- 
flanding ;  fo  they  fall  very  naturally  un- 
der three  diftincT:  heads.  For  either  the 
mind  combines  feveral  fimple  ideas  toge- 
ther in  order  to  form  them  into  one  com- 
plex idea,  in  which  the  number  and 
quality  of  the  ideas  united  are  principally 
confidered  ;    in    which  way  we   become 

poifeffed 


(    55     ) 

porTeffed  of  all  our  compound  ideas :  or 
it  fixes  upon  any  one  of  its  ideas,  whe- 
ther it  be  a  fimple  or  compound  idea,  or 
an  idea  of  a  fubltance,  and  leaving  out 
the  circumftances  of  time,  place,  real 
exigence,  and  whatever  renders  it  par- 
ticular, confiders  what  it  has  in  common 
with  others,  and  of  that  makes  an  idea 
which  will  apply  to  all  of  a  kind  ;  whence 
our  abdracl  or  univerfal  ideas  are  deriv- 
ed :  or,  laflly,  it  compares  things  one 
with  another,  examines  their  mutual  con- 
nections, and  thereby  furniihes  itfelf  with 
a  new  fet  of  ideas,  known  by  the  name 
of  relations  ;  which,  as  has  been  already 
remarked,  make  by  no  means  the  leaf] 
important  clafs  of  our  ideas. 


CHAP. 


.      (    3«    > 

CHAP.     II. 

Of  Terms  and  Definitions. 

Having  feen,  in  the  preceding  chap* 
ter,  how  our  ideas  are  acquired ;  let  us 
now  proceed  to  examine  how  they  are 
communicated.  Ideas  themfelves  are  not 
vifible,  nor  can  they  be  perceived  by  any 
outward  fenfe.  But  God,  defigning  us 
for  fociety,  and  to  have  fellowship  with 
thofe  of  our  kind,  has  provided  us  with 
organs  fitted  to  frame  articulate  founds, 
and  given  us  alfo  a  capacity  of  ufing 
thofe  founds,  or  terms,  as  figns  of  ideas. 
Hence  our  ideas,  which  otherwife  muft 
have  been  locked  up,  as  it  were,  in  our 
own  breads,  are  brought  forth  and  made 
to  appear.  For,  any  number  of  men 
having  agreed  to  make  ufe  of  the  fame 

founds 


(  37  ) 
founds  as  figns  of  the  fame  ideas,  it  is 
evident,  that  the  repetition  of  thefe 
founds  mud  excite  the  fame  ideas  in  them 
all.  When,  for  inflance,  any  train  of 
ideas  takes  poffeffion  of  m,y  mind,  if  the 
terms,  or  founds,  by  which  I  am  wont 
to  exprefs  them,  have  been  annexed,  by 
thofe  with  whom  I  converfe,  to  the  very 
fame  fet  of  ideas,  nothing  is  more  evi- 
dent, than  that  by  repeating  thofe  terms, 
according  to  the  tenor  of  my  ideas,  I 
fhall  raife  in  their  minds  the  fame  train 
that  has  taken  poffefTion  of  my  own. 
Hence,  by  barely  attending  to  what  paffes 
within  themfelves,  they  will  alfo  become 
acquainted  with  the  ideas  in  my  under- 
-  Handing,  and  have  them  in  a  manner  ex- 
pofed  to  their  view. 

So  that  we  here  clearly  perceive  how 
a  man  may  communicate  his  fentiments 
to  another  j  provided    the  language,  in 

which 


(  38  ) 
which  he  converfes,  be  copious  enough 
to  contain  words  appropriated  to  all  his 
ideas ;  and  provided  the  perfon,  to  whom 
he  fpeaks,  is  poffeffed  of  the  fame  ideas 
which  he  expreffes,  and  has  been  ac- 
cuftomed  to  connect  them  with  the  fame 
terms. 

But  as  this  is  not  always  the  cafe, 
and  as  we  may  often  have  occafion  to 
communicate  to  others  a  new  idea, — that 
is,  an  idea  that  has  never  yet  entered 
their  minds,  and  which  confequently  they 
cannot  as  yet  have  connected  with  any 
term  ;  it  may  be  alked,  how  fuch  an  idea 
can  poffibly  be  communicated  to  them, 
by  a  term  to  which  they  have  never  an- 
nexed any  idea,  and  which  of  courfe  can- 
not be  to  them  the  fign  of  an  idea. 

This  appears  to  be  a  difficulty ;  and, 
to  folve  it,  it  will  be  necelTary  to  obferve, 
firft,  that  no  word  can  be  to  any  man 

the 


(    39    ) 

the  fign  of  an  idea,  till  that  idea  comes 
to  have  a  real  exiftence  in  his  mind.  For 
words  being  only  fo  far  intelligible,  as 
they  denote  known  ideas ;  where  they 
have  none  fuch  to  anfwer  to  them,  there 
they  are  plainly  founds  without  figniflca- 
tion,  and  of  courfe  convey  no  informa- 
tion. But  no  fooner  are  the  ideas,  to 
which  they  belong,  produced  in  the  un- 
derstanding, than,  finding  it  eafy  to  con- 
nect them  with  the  eftablifhed  words,  we 
can  join  in  any  agreement  of  this  kind 
made  by  others,  and  enjoy  the  benefit  of 
their  difcoveries.  The  firlf  thing,  there- 
fore, to  be  confidered,  is,  how  thefe 
ideas  may  be  conveyed  into  the  mind, 
that,  they  being  there,  we  may  learn  to 
connect  them  with  the  appropriated 
founds,  and  fo  become  capable  of  under- 
ftanding  others  when  they  make  ufe  of 
thefe  founds  in  laying  open  and  communi- 
cating 


(     40     ) 

eating  their  thoughts.  Now  to  compre- 
hend diftinctly  how  this  may  be  done,  it 
will  be  neceffary  to  call  to  mind  the  be- 
fore mentioned  divifions  of  our  ideas  into 
iimple  and  complex.  And  firft,  as  to 
our  fimple  ideas,  it  has  been  already  ob- 
ferved,  that  they  can  find  no  admiffion 
into  the  mind,  but  by  the  original  foun- 
tains of  knowledge  \  fenfation,  and  con- 
fcioufnefs.  If  therefore  any  of  thefe  have 
as  yet  no  being  in  the  underftanding,  it 
will  be  impoifible  bywords  to  excite  them 
there.  A  man,  who  had  never  felt  the 
impreffion  of  heat,  could  not  be  brought 
to  comprehend  that  fenfation,  by  any 
thing  which  we  could  fay  to  explain  it. 
If  we  would  produce  the  idea  in  him,  it 
muft  be  by  applying  the  proper  object  to 
his  fenfes,  and  bringing  him  within  the 
influence  of  a  hot  body.  When  this  is 
done,  and  experience  has  taught  him  the 

fenfation, 


(     4i     ) 

fenfation,  to  which  men  have  annexed 
the  name,  heat,  this  term  then  becomes 
to  him  the  fign  of  that  idea;  and  he 
thenceforth  underftands  the  meaning  of 
the  term ;  which,  before,  all  the  words 
in  the  world  would  not  have  been  fuf- 
ficient  to  convey  into  his  mind.  The 
cafe  is  the  fame  with  refpecl:  to  light  and 
colours :  a  man  born  blind,  and  by  this 
misfortune  deftitute  of  the  only  convey- 
ance for  the  ideas  of  thefeobj eels, can  never 
be  brought  to  underftand  the  terms  by 
which  they  are  expreifed.  The  reafon 
is  plain  :  they  ftand  for  ideas  which  have 
no  exigence  in  his  mind ;  and  as  the 
organ,  appropriated  to  their  reception,  is 
wanting,  all  other  contrivances  are  vain, 
nor  can  thefe  ideas,  by  any  force  of  de- 
fcription,  be  excited  in  him. — But,  with 
our  complex  ideas,  it  is  quite  otherwifc. 
For  thefe  being  no  other  than  certain 
F  eombina- 


(     42      ) 

combinations  of  fimple  ideas  put  together 
in  various  forms ;  if  the  fimple  ideas,  out 
of  which  the  complex  ideas  are  made, 
have  already  got  admiflion  into  the  un- 
derstanding, and  the  terms  ferving  to  ex- 
prefs  them  be  known,  it  will  be  eafy,  by 
enumerating  the  feveral  ideas  included  in 
the  combination,  and  marking  the  order 
and  manner  in  which  they  are  united,  to 
raife  any  complex  idea  in  the  mind.  Thus 
the  idea  anfvvering  to  the  term,  rainbow, 
may  be  readily  excited  in  the  imagina- 
tion of  another,  who  has  never  feen  the 
appearance  itfelf,  by  defcribing  the  fi- 
gure, frze,  pofition,  and  order  of  co- 
lours ;  if  we  fuppofe  thefe  feveral  fimple 
ideas,  with  their  names,  fufflciently  known 
to  him. 

The  anfwer,  then,  to  the  queflion  pro- 
pofed  above,  is  now  fufficiently  obvious. 
If  the  new  idea,  which  we  wifh  to  com- 
municate 


(     43     )' 

municate  to  others,  be  a  fimple  idea,  we 
mult  refer  them  to  thofe  objects  in  nature 
whence  the  idea  is  to  be  obtained :  but, 
if  it  be  a  complex  idea,  its  meaning  may 
be  explained  by  enumerating  the  ideas 
included  in  it ;   that  is,  by  defining  it. 

And  here  we  fee  the  nature  and  ufe  of 
definitions.  They  are  ufed  to  unfold  a 
complex  idea ;  and  two  things  are  re- 
quired in  them  :  lirfl,  that  all  the  fimple 
ideas,  out  of  which  the  complex  one  is 
formed,  be  diftinctly  enumerated ;  and, 
fecondly,  that  the  order  and  manner  of 
combining  them  be  clearly  explained. 
Where  a  definition  has  thefe  requifites, 
nothing  is  wanting  to  its  perfection  ;  be- 
caufe  every  one,  who  reads  it,  and  un- 
derftands  the  terms,  feeing  at  once  what 
ideas  he  is  to  join  together,  and  alfo  in 
what    manner,    can,    at   pleafure,  -form, 

in 


C     44     ) 

in  his  own  mind,  the  complex  idea  an* 
fwering  to  the  term  defined. 

But  this  rule,  though  it  extends  to  all 
poffible  cafes,  and  is  indeed  that  alone  to 
which  we  can  have  recourfe  where  any 
doubt  or  difficulty  arifes,  it  is  not,  how- 
ever, neceffary,  or  even  expedient,  to 
praclife  in  every  particular  inftance.  Many 
cf  our  ideas  are  extremely  complex  ;  and, 
of  courfe,  to  enumerate  all  the  fimple 
ideas,  out  of  which  they  are  formed, 
would  be  a  very  troublefome  and  tedious 
work.  For  which  reafon,  logicians  have 
eftabliflied  a  certain  compendious  mode  of 
defining ;  of  which,  it  may  not  be  amifs 
to  give  here  a  fhort  account.  If  the  thing 
to  be  defined  be  a  fpecies,  they  give  the 

NEAREST     GENUS     and     the     SPECIFICK 

difference  ;  or,  in  other  words,  they 
refer  it  to  its  neareft  genus,  and  then  add 
thofe  circumftances  that  make  the  fpecies, 

which 


(     45     ) 

which  they  are  defining,  to  differ  from 
every  other  fpecies  belonging  to  that 
genus.  For,  as  the  idea  of  a  genus  is 
formed  by  dropping  what  is  peculiar  to 
each  of  the  feveral  fpecies  referred  to  it, 
and  retaining  thofe  particulars  which  they 
all  poffefs  in  common  ;  fo,  on  the  other 
hand,  by  adding  to  the  genus  what  is 
peculiar  to  any  one  of  the  fpecies  includ- 
ed in  it,  we  form  an  adequate  idea,  and 
give  a  complete  definition,  of  that  fpecies. 
In  like  manner,  if  the  thing  to  be  defined 
be  an  individual,  the  logical  definition 
will  confilt.  of  the  the  species  and  the 
numerical  difference  ;  or,  in  other 
words,  of  the  fpecies,  and  thofe  particu- 
lars that  diilinguiili  the  individual  which 
we  are  defining,  from  every  other  in- 
dividual belonging  to  that  fpecies.  For, 
as  the  idea  of  a  fpecies  is  formed  by  drop- 
ping what  is  peculiar  to  the  feveral  in- 
dividuals 


(     46     ) 

dividuals  referred  to  it,  and  retaining 
thofe  particulars  only  which  they  polTefs 
in  common  ;  fo,  by  adding  to  the  fpecies 
what  is  peculiar  to  any  one  of  the  indi- 
viduals included  in  it,  we  form  an  ade- 
quate idea,  and  give  a  complete  defini- 
tion, of  that  individual. 

We  mail  conclude  with  obferving,  that 
definitions  have  been  diftinguiflied  into 
two  kinds ;  the  definition  of  the 
name,  and  the  definition  of  the 
thing.  When  the  term  to  be  defined, 
refers  to  the  idea  of  the  writer  or  fpeak- 
er,  and  the  definition  is  defigned  to  fhow 
what  idea  he  connects  with  a  certain 
term,  it  is  a  definition  of  the  name.  And 
fuch  definitions  are  faid  to  be  arbitrary ; 
becaufe,  as  words  are  not  natural,  but 
merely  artificial,  figns  of  ideas,  every 
man  is  at  liberty  to  annex  to  a  term  what 
idea  he  pleafes.     But  where  the  reader, 

or 


C     47      ) 

or  hearer,  is  fuppofed  to  know  that  a 
certain  term  is  connected  with  a  particu- 
lar idea,  and  where  the  defign  of  the  de- 
finition is  to  unfold  that  idea,  that  the 
nature  of  the  thing  of  which  it  is  the  type 
or  refemblance,  may  be  fully  underftaod, 
it  is  a  definition  of  the  thing.  And  fuch 
a  definition  is  not  arbitrary,  becaufe  the 
idea  of  any  thing  mould  be  conformable 
to  that  thing,  and  the  definition  confor- 
mable to  the  idea. 


PART    II. 

Of  Judgment. 

All  our  knowledge  may  be  reduced 
to  two  heads ;  our  ideas  of  things,  and 
the  judgments  which  we  form  with  refpect 

to 


(     48     ) 

to  them.  Of  our  ideas,  and  of  terms 
and  definitions  by  which  they  are  commu- 
nicated, we  have  already  treated.  We 
come  now  to  fpeak  of  our  judgments  ; 
and  of  propositions,  by  which  they  are 
communicated.  And  here  it  will  be  pro- 
per to  confider,  firft,  the  feveral  grounds 
of  human  judgment ;  and,  fecondly,  the 
different  forts  of  propofitions. 


CHAP.     I. 

Of  the  grounds  of  human  judgment ;  or, 
in  other  words,  of  the  different  sorts 

OF  EVIDENCE. 

Judgment  is  that  operation  of  the 
mind  by  which  we  compare  two  or  more 
ideas  together,  with  a  view  to  determine 
whether  they  agree   or  difagree.     But 

alth6ugh, 


(     49     ) 

although,  in  every  aft  of  judgment,  it  is 
neceffary  to  bring  two  or  more  ideas 
together,  and  place  them,  as  it  were, 
over  againfl  each  other;  yet,  the  mere 
comparing  of  two  ideas  together  is  not 
the  evidence  of  their  agreement  or  difa- 
greement.  What  then,  it  may  be  aiked, 
is  this  evidence  ?  or  rather,  (^as  one  fort 
of  truth  is  fupported  by  one  fort  of  evi- 
dence, and  another  by  another),  What 
are  the  different  forts  of  evidence  ? 

To  affifl  us  in  judging  of  this  fubjeft, 
it  will  be  neceffary  to  obferve,  that  all 
the  objefts  of  the  human  underflanding 
are,  either  abstracl  notions  of  quantity  and 
number ,  or  things  really  existing.  Of  the 
relations  of  thefe  abftraft  notions,  all  our 
knowledge  is  certain  ;  being  founded  on 
mathematical  evidence.  Of  things  really 
exifting,  we  judge,  either  from  our  own 
experience,  or  from  the  experience  of 
G  other 


(    5°    ) 

other  men.  Judging  of  real  exiftencc 
from  our  own  experience,  we  attain  either 
certainty  or  probability.  Our  knowledge 
of  real  things  is  certain,  when  fupported 
by  the  evidence  of  external  fenfe,  con- 
icioufnefs,  and  memory  ;  and  when  from 
effects  we  infer  caufes.  Our  knowledge 
of  real  things  is  probable,  when,  from 
facts  whereof  we  have  had  experience, 
we  infer  facts  of  the  fame,  or  a  fimilar, 
kind,  not  experienced.  Judging  of  real 
exiflence  from  the  experience  of  other 
men,  we  have  the  evidence  of  their  tefii- 
mony.  And  thus  it  appears,  that  aU 
forts  of  evidence  productive  of  real  know- 
ledge, may  be  reduced  to  feven  :  i.  Ma- 
thematical evidence,  i.  The  evidence  of 
external  fenfe.  3.  The  evidence  of  con- 
fcioufnefs.  4.  The  evidence  of  memory, 
5.  That  evidence  which  we  have,  when 

from 


(     5*     ) 

from  effecls  we  infer  caufes.  6.  The  evi- 
dence of  testimony,     7.  Probable  evidence. 

Of  IvIATHEMATICAL  EVIDENCE  there 

are  two  forts ;  intuitive^  and  demonstrat- 
ive. Mathematical  evidence  is  intuitive, 
when,  from  the  very  nature  of  the  ideas 
compared,  it  appears,  at  firfl  view,  that 
they  mu(t  neceflarily  agree  or  difagree. 
Mathematical  demonftrative  evidence  is 
direel,  or  indirtcl.  When  a  conclufion 
is  inferred  from  principles  which  render 
it  neceflarily  true,  the  demonflration  is 
direct.  When,  by  fuppofing  a  given 
propofition  falfe,  we  are  neceflarily  led 
into  an  abfurdity,  it  is  called  indirect, 
apagogical,  or  ducens  in  abfurdum.  Now 
that  mud  be  true,  which  we  cannot, 
without  abfurdity,  fuppofe  to  be  falfe. 
And  therefore  both  forts  of  demonflra- 
tion  are  equally  good,  becaufe  equally 
productive  of  abfolutc  certainty. 

All 


(      52      ) 

All  mathematical  proof  is  founded  upon 
axioms,  or  felf-evident  proportions,  the 
contraries  of  which  are  inconceivable. 
And  this  fort  of  proof  feems  to  be  pecu- 
liar to  the  fciences  that  treat  of  quantity 
and  number  ;  and  therefore,  in  no  other 
fcience  is  the  mathematical  method  of 
proof  to  be  expected.  For,  in  the  other 
fciences,  in  moft  of  them  at  lead,  truth 
and  its  contrary  are  equally  conceivable. 
That  Julius  Csefar  died  a  natural  death  is 
as  eafy  to  be  conceived,  as  that  he  was 
murdered  in  the  fenate-houfe.  I  feel  a 
hard  body,  I  do  not  feel  a  hard  body ; 
I  fee  a  white  colour,  I  do  not  fee  a  white 
colour ;  are  all  equally  conceivable  :  and 
yet  may  be  either  true  or  falfe  according 
to  circumftances.  We  may  conceive  that 
the  fun,  after  fetting  to-night,  will  never 
appear  again,  or  that  any  particular  man 
will  never  die  :  and  yet  we  confider  death 

as 


(    53    ) 

as  what  mud  inevitably  happen  to  every 
man,  and  the  rifing  of  the  fun  to-morrow 
as  fo  certain,  that  no  rational  being  can 
doubt  of  it.  Though,  therefore,  the 
mathematical  method  of  proof  is  to  be 
found  in  the  mathematical  fciences  only, 
yet  fatisfactory  proof  may  be  found  in 
any  other  fcience :  and  is  actually  found, 
in  every  part  of  knowledge  that  deferves 
the  name  of  fcience. 

The  evidence  of  external  sense, 
no  lefs  than  mathematical  evidence,  pro- 
duces abfolute  certainty ;  though  in 
another  way.  Our  conception  of  exter- 
nal things  is  attended  with  an  irrefiflible 
belief,  that  they  exift,  and  are  what 
they  appear  to  be.  When  I  fee  a  man 
or  a  horfe,  I  can  no-  more  doubt  of  his 
exiftence,  than  of  my  own  ;  and  my  own 
1  believe  with  as  full  aflurance  as  that 
two  and  two  are  four.     The  exiftence  of 

body 


(     54    ) 

body  is  a  felf-evident  fact.  It  needs  no 
proof;  for  to  difbelieve  or  doubt  of  it 
is  impoflible :  and  it  admits  of  none ; 
becaufe  we  know  of  nothing  more  evident 
to  prove  it  by. 

The  EVIDENCE  OF   INTERNAL  SENSE, 

or  consciousness,  does  alfo  produce 
abfolute  certainty.  That  we  have  within 
us  a  thinking  and  active  principle,  called 
a  foul  or  mind ;  which  is  the  fame  thing 
to-day  as  it  was  yefterday ;  is  confcious 
of  its  own  thoughts ;  and  exercifes  a 
variety  of  faculties  different  in  their  ob- 
jects and  manner  of  operation  ;  are  all  of 
them  fuggeftions  of  internal  fenfe  or  con- 
fcioufnefs,  which  we  believe  becaufe  we 
feel  them  to  be  true  ;  and  which  if  we 
were  not  to  believe,  would  bring  on  us 
the  charge  of  irrationality. 

The  evidence  of  memory  does  alfo 
produce  abfolute  certainty.     A  child  be- 
lieves, 


(    55    ) 

iieves,  without  any  doubt,  that,  what  he 
remembers  diftinclly  to  have  feen  or 
heard,  he  really  did  fee  or  hear.  And 
he  believes  this,  not  becaufe  he  has  been 
told  that  he  may  fafely  truft  his  memory  j 
but  becaufe  the  law  of  his  nature  deter- 
mines him,  of  his  own  accord,  to  believe 
his  memory  as  well  as  his  fenfes.  Indeed 
if  we  were  to  diftruft  our  memory,  or 
treat  it  as  a  fallacious  faculty,  our  fenfes 
would  be  of  little  ufe  to  us,  and  we 
fliould  be  incapable  both  of  knowledge 
and  experience,  and  alfo  of  reafoning ; 
for  we  cannot  be  fatisfled  with  a  proof, 
unlefs  we  remember  the  fteps  of  it,  and 
believe  that  on  that  remembrance  we 
may  depend.  Thoughts  remembered 
may  decay  through  length  of  time,  and 
at  lad  vanifh  ;  but,  of  an  event  or  object, 
that  part  which  we  diftinc"tl,y  remember, 
we  believe  to  have  been  real.     We  may 

forget 


(     56    ) 

forget  the  whole  fubjecl:  of  a  book,  and 
yet  remember,  and  confequently  believe, 
that  we  read  it.  We  may  forget  the 
proofs  of  a  propofition,  and  yet  remem- 
ber that  it  was  formerly  proved  to  our 
fatisfa&ion,  and  acquiefce  in  it  accord- 
ingly. If  in  conceiving  any  event  or 
object,  we  are  uncertain  whether  we  re- 
member or  only  imagine,  belief  is  fuf- 
pended  and  we  remain  in  doubt ;  but  no 
fooner  are  we  confcious  that  we  remem- 
ber, than  belief  inflantly  takes  place; 
and  we  fay,  I  am  certain  it  was  fo,  for 
now  I  remember  it  diftinctly. 

As  tO  THE  EVIDENCE  THAT  WE  HAVE 
WHEN  FROM  EFFECTS  WE  INFER  CAUS- 
ES, we  may  obferve,  that  the  law  of  our 
nature  determines  us  to  believe,  that 
whatever  begins  to  exist,  proceeds  from 
fome  caufe.  If,  on  going  home,  I  mould 
find,  on  the  table,  a  book,  which  I  never 

.    faw 


(  57  ) 
faw  before,  it  would  occur  to  me  as  ab- 
folutely  certain,  that  fome  caufe  had 
brought  and  fome  perfon  made  it.  For 
if  I  were  to  be  told,  that  nobody  brought 
it,  and  that  it  never  was  made,  I  fliould, 
without  hefitation,  declare  fuch  a  thing 
to  be  not  only  abfurd  but  impoffible ; 
and  there  is  not  one  rational  being  who 
in  this  would  refufe  to  concur  with  me. 
Even  children  think  in  this  manner,  and 
fome  are  very  inquifitive  into  the  caufes 
of  things :  a  proof  that  it  is  not  experi- 
ence merely  which  leads  us  to  infer  the 
caufe  from  the  efTecl:.  If  the  book,  which 
I  fuppofed  myfelf  to  find,  contained  wife 
obfervations,  and  was  well  printed  and 
bound,  I  mud  of  neceffity  believe,  that 
the  author,  printer,  and  binder,  were 
pofTeffed  of  wifdom  and  /kill  equal  to  the 

efTecl:  produced. That  being  whom  we 

believe  to  have  proceeded  from  no  caufe 
H  but 


(     58     ) 

but  the  neceffity  of  his  own  nature,  and  ta 
be  felf-exiftent,  and  on  all  other  beings  in- 
dependent, we  mud  alfo  believe  to  have 
exifted  from  eternity,  or  in  other  words, 
to  have  had  no  beginning.  For  if  every 
thing  that  had  a  beginning,  proceeded 
from  fome  caufe,  that  which  proceeded 
from  no  caufe,  could  have  had  no  begin- 
ning. 

Probable  evidence  is  of  two  forts. 
One  is,  when  from  facts  whereof  we 
have  had  experience,  we  infer  facts  of 
the  fame  kind  not  experienced.  It  is  na- 
tural for  us  to  think,  that  the  courfe  of 
things  whereof  we  have  had  experience, 
and  now  have,  will  continue,  unlefs  we 
have  pofitive  reafon  to  believe  that  it  will 
be  altered.  This  is  the  ground  of  many 
of  thole  opinions  which  we  account  quite 
certain.  That  to-morrow  the  fun  will 
rife,  and   the   fea  ebb  and   flow ;    that 

night 


(    59    ) 

night  will  follow  day,  and  fpring  fucceed 
lhe  winter ;  and  that  all  men  will  die ; 
are  opinions  amounting  to  certainty  :  and 
yet  we  cannot  account  for  them  other- 
wife  than  by  faying,  that  fuch  has  been 
the  courfe  of  nature  hitherto,  a£nd  we 
have  no  reafon  to  believe  that  it  will  be 
altered.  When  judgments  of  this  kind 
admit  no  doubt,  as  in  the  example  given 
above,  our  conviction  is  called  moral 
certainty.  I  am  morally  certain,  that 
the  fun  will  rife  to-morrow,  and  (ct  to- 
day, and  that  all  men  will  die,  &c.  The 
inftances  of  part  experience,  on  which 
thefe  judgments  are  founded,  are  innu* 
merable  ;  and  there  is  no  mixture  of  con- 
tradictory inftances  which  might  lead  us 
to  expect  a  contrary  event.  But  if  the 
experiences,  on  which  we  ground  our 
opinions  of  this  fort,  are  but  few  in  num- 
ber, or  mixed  with  contradictory  experi- 
ences, 


C   60   ) 

ences,  in  this  cafe  we<io  not  confider  the 
future  event  as  morally  certain,  but  only 
more  or  lefs  probable  according  to  the 
greater  or  lefs  furplus  of  favourable  in- 
ftances.— The  other  fort  of  probable  evi- 
dence, which  is  termed  analogical,  is, 
when  from  facts  whereof  we  have  had 
experience,  we  infer  facts  of  a  Jimilar 
kind  not  experienced  ;  or,  in  other  words, 
when  we  expect  fimilar  events  in  fimilar 
circumftances.  For  example,  we  think 
it  probable  that  the  planets  are  inhabited, 
they  being  in  all  refpe&s  fo  like  our  earth. 
The  force  of  an  argument  from  analogy 
is  in  proportion  to  the  degree  of  likenefs, 
that  there  is  between  the  caXtfrom  which 
we  argue,  and  the  cafe  to  which  we 
argue.  In  the  example  given,  the  cafe 
from  which  we  argue,  is  the  circumftance 
of  this  earth's  being  a  planet,  warmed 
and  enlightened  by  the  fun,  and  inhabited 

by 


f    61     J 

by  many  varieties  of  living  creatures ; 
and  the  cafe  to  which  we  argue,  is  that 
of  the  other  planets,  which  being  in  all 
other  refpe&s  fo  fimilar  to  our  earth,  we 
think  it  highly  probable  that  they  mufl 
refemble  it  in  this,  in  being  the  habita- 
tion of  percipient  beings.  A  man  who 
thinks,  as  Epicurus  did,  that  they  are 
no  bigger  than  they  appear  to  his  eye, 
can  have  no  notion  of  their  being  inhabit- 
ed, becaufe  to  him  they  mufl:  appear  in 
every  refpect  fo  unlike  our  earth.  And 
if  we  were  to  argue  with  him,  in  order 
to  bring  him  over  to  our  opinion,  we 
fhould  begin  by  explaining  to  him  thofe 
particulars,  wherein  the  earth  and  the 
other  planets  refemble  each  other.  As 
foon  as  he  underflands  thefe  particulars 
as  well  as  we,  he  will,  of  his  own  ac- 
cord, admit  the  probability  cf  our 
opinion. 

Another 


(      62      ) 

Another  and  the  laft  -fpecies  of  evi- 
dence, upon  which  we  are  to  remark  in 
this  place,  is  testimony.  It  is  natural 
for  a  man  to  fpeak  as  he  thinks  ;  and  it 
is  eafy,  like  walking  forward.  One  may- 
walk  backward,  or  fideways ;  but  it  is 
uneafy,  and  a  fort  of  force  upon  nature  : 
and  the  fame  thing  is  true  of  fpeaking 
one  thing  and  thinking  another. — It  is 
alfo  natural  for  us  to  believe  what  others 
feriouily  tell  us.  We  truft  the  word  of 
a  man  of  whofe  veracity  we  have  had  ex- 
perience ;  but  we  alfo  credit  teftimony 
previoufly  to  fuch  experience ;  for  child- 
ren, who  have  the  leafl  experience,  are 
the  mod  credulous.  It  is  from  having 
had  experience  of  the  ^difhonefty  of  men, 
and  of  the  motives  that  tempt  them  to  it, 
that  we  come  to  difbelieve  or  to  diftruft 
what  they  fay.  In  general,  when  we 
doubt  a  man's  word,  we  have  fome  reafon 

for 


(     63     1 

for  it.  We  think  that  what  he  fays  is  in- 
credible in  itfelf ;  or,  that  there  is  fome 
motive  or  temptation  which  inclines  him 
in  the  prefent  cafe  to  violate  truth  ;  or, 
that  he  is  not  a  competent  judge  of  the 
matter  in  which  he  gives  teftimony ;  or, 
laftly,  we  diftruft  him  now,  becaufe  we 
know  him  to  have  been  a  deceiver  for- 
merly. 

Faith  in  teftimony  often  rifes  to  ab- 
folute  certainty.  Of  places  and  perfons 
we  never  faw,  and  know  nothing  but 
from  the  teftimony  of  others,  we  believe 
many  things  as  firmly  as  we  believe  our 
own  exiftence.  This  happens,  when  the 
teflimonies  of  men  concerning  fuch  places 
and  perfons,  are  fo  many,  and  fo  con- 
fident, that  it  feems  impoffible  they 
fliould  be  fictitious. — When  a  number  of 
perfons,  not  a&ing  in  concert,  having  no 
intereft  to  difguife  what  is  true,  or  to 

affirm 


f  64  ) 

affirm  what  is  falfe,  and  competent  judges 
of  what  they  teftify,  concur  in  making 
the  fame  report,  it  would  be  accounted 
folly  to  difbelieve  them,  efpecially  if  what 
they  teflify  be  credible  in  itfelf.  Even 
when  three,  or  when  two  witneffes,  fepa- 
rately  examined,  having  had  no  oppor- 
tunity to  concert  a  plan  beforehand, 
concur  in  the  fame  declaration,  we  be- 
lieve them,  though  we  have  had  no  ex- 
perience of  their  veracity ;  becaufe  we 
know,  that  in  fuch  a  cafe  their  declara- 
tions would  not  be  confident,  if  they 
were  not  true. — In  regard  to  an  impof- 
fible  thing,  we  mould  not  believe  our 
own  fenfes,  nor  confequently  human  tef- 
timony.  Miraculous  fa  els,  however,  are 
not  to  be  ranked  with  impoilibilities.  To 
raife  a  dead  man  to  life,  to  cure  blind- 
nefs  with  a  touch,  to  remove  lamenefs, 
er  a  difcafe,    by  fpeaking  a  word,  are 

miracles : 


(     65     ) 

miracles :  but  to  divine  power  as  eafy,  as 
to  give  life  to  an  embryo,  make  the  eye 
an  organ  of  fight,  or  caufe  vegetation  to 
revive  in  the  fpring.  If  it  be  afked, 
what  evidence  is  fufficient  to  eftablifh  the 
truth  of  miraculous  events  fuch  as  thefe, 
we  anfwer,  that  every  event  admits  of  a 
proof  from  human  teftimony,  which  it  is 
poffible  for  a  fufficient  number  of  com- 
petent witnelfes  to  fee  and  to  hear. 


CHAP.    IL 


Of  Proportions,  and  their  Various  Kinds. 

A  proposition  is  a  judgment  of  the 
mind  expreifed  in  words.  Now  as  our 
judgments  include  at  leait  two  ideas,  one 
of  which  is  affirmed  or  denied  of  the 
other  3  fo  muft  a  proportion  have  terms 
1  anfwer  in  2 


(     66     ) 

anfwering  to  thefe  ideas.  The  idea,  of 
which  we  affirm  or  deny,  and  of  courfe 
the  term  expreffing  that  idea,  is  called 
the  subject  of  that  proportion.  The 
idea  affirmed  or  denied,  as  alfo  the  term 
anfwering  to  it,  is  called  the  predi- 
cate. Thus,  in  the  proportion,  God  is 
omnipotent^ — God  is  the  fubjecr,  it  being  of 
him  that  we  affirm  omnipotence ;  and 
omnipotent  is  the  predicate,  becaufe  we 
affirm  the  idea,  expreiTed  by  that  word, 
to  belong  to  God.  And  that  word,  in 
a  proportion,  which  connects  the  fubjecT: 
and  predicate  together,  is  called  the 
copula  ;  as  in  the  above  mentioned  pro- 
portion, where  is  is  the  copula,  and  llg- 
nifi.es  the  agreement  of  the  ideas  of  God 
and  omnipotence.  But  if  we  mean  to 
feparate  two  ideas,  then,  befides  the  co- 
pula we  mud  alfo  ufe  fome  particle  of  ne- 
gation to  exprefs  this  repugnance.     Of 

this 


f  .67  ) 

this  kind,  the  proportion,  man  is  not  per- 
feci,  may  ferve  as  an  example  ;  where  the 
idea  of  perfeclion  being  intended  to  be  fe- 
parated  from  the  idea  of  man,  the  nega- 
tive particle  not  is  inferted  after  the  co- 
pula, to  fignify  the  difagreement  between 
the  fubjeft  and  the  predicate.  But  al- 
though every  proportion  neceflarily  con- 
fids  of  thefe  three  parts,  it  is  not  alike 
necefTary  that  they  be  all  feverally  exprefs- 
ed  in  words ;  becaufe  the  copula  is  often 
included  in  the  term  of  the  predicate,  as 
when  we  fay  he  writes,  which  imports 
the  fame  as  he  is  writing.  And,  in  the 
Latin  language,  a  fingle  word  has  often 
the  force  of  a  whole  fentence ;  where 
ambulat,  for  example,  is  the  fame  as  ilk 
est  ambulans  ;  amo,  as  ego  Jam  amqns. 
Proportions  are  either  affirmative 

Or    NEGATIVE,     UNIVERSAL    Or    PARTI- 
CULAR,   ABSOLUTE     01*    CONDITIONAL, 

SIMPLE 


(     68     ) 

SIMPLE  Or  COMPOUND,  SELF-EVIDENT 
Or  DEMONSTRABLE,  SPECULATIVE  Or 
PRACTICAL. 

An  affirmative  proportion  conne&s  the 
predicate  with  the  fubjecl: ;  as,  a  stone  is 
heavy :  a  negative  feparates  them ;  as 
God  is  not  the  author  of  evil.  And  as,  in 
all  cafes,  the  predicate  muft  either  be 
connected  with  the  fubjecl:,  or  feparated 
from  it,  it  is  evident  that  all  proportions 
fall  under  thefe  two  divifions. 

An  univerfal  proportion  is  a  propo- 
rtion which  has  for  its  fubjecl:  fome  gene- 
ral term  taken  in  its  full  extent ;  fo  that 
the  predicate  agrees  with  all  the  indivi- 
duals comprehended  under  it,  if  it  be  a 
proper  fpecies, — and  with  all  the  feveral 
fpecies  and  their  individuals,  if  it  be  what 
is  termed  a  genus.  Thus,  all  animals 
have  a  power  of  beginning  motion,  is  .an 
univerfal  propofition ;  animals,  the  fub- 
jecl, 


(     69     ) 

je<5t,  being  a  general  term  without  any 
mark  of  limitation,  and  by  confequence 
taken  in  its  full  extent :  hence  the  power 
of  beginning  motion  may  be  affirmed  of 
all  the  feveral  fpecies  of  animals,  as  of 
quadrupeds,  birds,    infects,  fillies,  &c.  ; 
and  of  all  the  individuals  of  which  thefe 
different  fpecies  confift,  as  of  this  hawk, 
that  horfe,  and  fo  on  with  refpedt  to  the 
reft.      A  particular  propofition    is    one, 
which  has,  in  like  manner,  fome  general 
term  for  its  fubject ;  but  with  a  mark  of 
limitation  added,  to  denote  that  the  pre- 
dicate agrees  with  fome  only  of  the  in- 
dividuals comprehended  under  it,  if  it  be 
a  fpecies, — or   with    one  or    more,   not 
with  all,  of  the  fpecies  belonging  to  it, 
if  it  be  a  genus.     Thus,  fome  stones  are 
heavier  than  iron  ;  fome  men  have  an  un- 
common Jhare  of  prudence. Where  the 

fubject  of  a  propofition  is  an  individual, 

it 


i    7°    ) 

it  is  called  a  singular  proposition. 
Of  this  nature  are  the  following,  Sir 
Ifaac  Newton  was  the  inventor  of  find  ions  ; 
This  book  contains  many  ufeful  truths.  And 
fach  proportions,  though  more  particular 
than  thofe  which  are  generally  called  (o, 
come  under  the  fame  rule  with  univerfals ; 
becaufe,  in  them,  the  fubject  is  taken  in 
its  full  extent. 

It  has  been  already  obferved,  that  all 
propofitions  are  either  affirmative  or  ne- 
gative :  it  is  equally  evident,  that,  in 
both  cafes,  they  may  be  univerfal  or  par- 
ticular. Hence  arifes  that  celebrated  four- 
fold divifion   of  them,  into  universal 

AFFIRMATIVE,  UNIVERSAL  NEGATIVE; 
PARTICULAR  AFFIRMATIVE,  and  PAR- 
TICULAR negative.  And,  in  forming 
fyllogifms,  it  has  become  a  cuftom,  in 
the  fchools,  to  make  ufe  of  the  four 
vowels,  a,  e,  /,  o9  to  denote  thefe  va- 
rieties : 


(    7*     ) 

rieties :  #,  to  denote  an  univerfal  affir- 
mative, as  all  good  men  are  esteemed ;  e9 
an  univerfal  negative,  as,  no  man  is  in- 
fallible;  /,  a  particular  affirmative,  as, 
fome  men  are  wife,  o9  a  particular  nega- 
tive, as,  fome  men  are  not  honest. 

"  Afferit  a,   negat   e,   verum  generaliter 

amba:" 
"  Afferit  i,    negat   o,  fed  particulariter 

ambo." 

The  diftinclion  of  propofitions  into  uni- 
verfal and  particular,  is  called  their 
quantity  ;  and  into  affirmative  and  ne- 
gative, their  quality. 

Abfolute  propofitions  are  thofe  in 
.which  we  affirm,  that  fome  property  is 
infeparable  from  the  idea  of  the  fubject  ', 
as,  lead  is  heavy.  Conditional  propo- 
fitions are  thofe  in  which  the  predicate  is 
not  neceffarily  connected  with  the  fub- 

jecr, 


(     72     )     • 

je&,  and  can  be  affirmed  of  it  on  fome 
condition  only,  diftinft  from  the  idea  of 
the  fubjecl: ;  as,  if  a  stone  be  expofed  to  the 
rays  of  the  fun,  it  will  contracl  a  degree 
of  heat.  And  here  we  are  to  obferve, 
that  all  conditional  proportions  confift  of 
two  diftincl:  parts  :  one,  expreffing  the 
condition  upon  which  the  predicate  agrees 
,  or  difagrees  with  the  fubjecl: ;  as,  in  the 
example  before  us,  if  a  stone  be  expofed  to 
the  rays  of  the  fun  :  the  other,  joining  or 
disjoining  faid  predicate  and  fubjecl: ;  as, 
in  the  fame  example,  it  will  contracl  a 
degree  of  heat.  The  firft  of  thefe  parts 
is  called  the  antecedent  \  the  fecond,  the 
confequent. 

When  a  proportion  has  but  one  fub- 
jecl: and  one  predicate,  it  admits  of  no 
fubdivifion,  and  is  faid  to  be  fimple. 
When  it  has  more  than  one  fubjecl:,  or 
more  than  one  predicate  \  or  has  feveral 

fubjeets 


(    73    ) 

fubjefts  and  predicates ;  it  is  faid  to  be 
compound.  If  it  have  one  fubjecl  and 
more  than  one  predicate, — or,  vice  verfa, 
one  predicate  and  more  than  one  fubjecl:, 
— it  may,  in  the  one  cafe,  be  refolved 
into  as  many  fimple  proportions  as  there 
are  predicates, — and,  in  the  other,  into 
as  many  as  there  are  fubje&s ;  as  will  be 
obvious  from  the  following  examples  : 
The  praclice  of /wearing  in  common  ccnvcr- 
fation,  is  abfurd,  unmannerly,  and  im- 
pious ;  neither  kings  nor  people  are  exempt 
from  death.  Nor  is  it  lefs  evident,  that 
if  a  propofition  confifts  of  feveral  fubje&s 
and  predicates,  it  may  be  refolved  into  as 
many  fimple  proportions,  as  there  are 
fubje&s  and  predicates.  Compound  pro- 
portions are  of  two  kinds ;  copulative, 
and  disjunctive.  A  copulative  propo- 
rtion takes  place,  where  the  fubjecls  and 
predicates  are  fo  joined  together,  that 
K  they 


(     74     ) 

they  may  be  all  feverally  affirmed  or  de- 
nied of  each  other.  Of  this  nature  are 
the  examples  which  have  been  jufl  given. 
A  disjunctive  proportion  compares  feveral 
predicates  with  the  fame  fubje£l9  and  af- 
firms that  one  of  them  neceiTarily  belongs 
to  it,  but  without  determining  which  ; 
as,  this  world  either  exists  of  itfelf  or  is 
the  work  of  fome  allwife  and  powerful 
caufe.  It  is  the  nature  of  all  propofitions 
of  this  clafs,  that,  upon  determining  the 
particular  predicate,  the  reft  are  of  courfe 
to  be  removed  ;  or,  if  all  the  predicates 
but  one  be  removed,  that  one  neceiTarily 
takes  place  :  thus,  in  the  example  given 
above,  if  we  allow  the  world  to  be  the 
work  of  fome  wife  and  powerful  caufe, 
we  of  courfe  deny  it  to  be  felf-exiftent ; 
or,  if  we  deny  it  to  be  felf-exiflent,  we 
mud  neceiTarily  admit,  that  it  was  pro- 
duced by  fome  wife  and  powerful  caufe. 

A  pro- 


(    75    ) 

A  propofition  is  felf-evident,  when, 
without  any  invefligation  or  proof,  the 
truth  of  it  is  obvious  at  firfl  view.  When 
we  affirm,  for  inftance,  that  a  fart  of 
any  thing  is  lefs  than  the  whole,  or  that 
men  exist ,  and  other  animals  ;  whoever 
underflands  the  terms  made  ufe  of,  per- 
ceives, at  the  firfl  view,  the  truth  of 
what  is  afTerted  ;  nor  can  he,  by  any 
efforts,  bring  himfelf  to  believe  the  con- 
trary. A  demonftrable  propofition  is  one, 
'  the  truth  of  which  is  not  immediately 
perceived  by  the  mind,  but  may  be  made 
to  appear  by  means  of  other  propofitions 
more  known  and  obvious,  whence  it  fol- 
lows as  an  unavoidable  confcquence. 

A    fpeculative    propofition    affirms    or 
denies  fome  property  of  its   fubjecl,   as 
when  it  is  affirmed,  that  the  radii  of  a 
circle  are  all  equal.     A  practical  propo 
fition  afferts  that  fomething  may  be  don- 

o 


(    76    ) 

or  effected ;  as,  that  a  right  line  may  be 
drawn  from  one  point  to  another.  And 
from  this  lafl  diftin&ion  arifes  a  four- 
fold divifion  of  mathematical  proportions, 

into  SELF-EVIDENT  SPECULATIVE,  and 
SELF-EVIDENT  PRACTICAL  J  DEMON- 
STRABLE SPECULATIVE,  and  DEMON- 
STRABLE practical.  Self-evident  fpe- 
culative  propofitions  are  called  axioms; 
and  felf-evident  practical  proportions, 
postulates  :  demonftrable  fpeculative 
propofitions,  theorems  ;  and  demon- 
ftrable practical  propofitions,  problems. 


PART 


(    77    ) 


PART    III. 

Of  Reafoning. 

The  fubject  of  this  part  of  Logick  is 
an  extcnfive  one;  and  to  difcufs  it  fully 
would  require  much  time.  We  fliall  con- 
tent ourfelves  with  explaining  what  is 
meant  by  reafoning,  and  giving  fome  ac- 
count of  various  kinds  of  fyllogifms,  which 
are  ac*ts  of  reafoning  exprefTed  in  words. 
To  which  we  fliall  fubjoin  fuch  of  the 
fophifms,  or  falfe  arguments,  as  are  the 
mofl  remarkable. 


CHAP. 


(     78     ) 


CHAP.     I. 

OfReafoning,  and  the  Parts  of  which  it 
consists. 

It  has  been  already  obferved,  that,  in 
comparing  two  ideas  together,  it  will 
fometimes  happen,  that  their  agreement 
or  difagreement  cannot  be  immediately 
difcerned.  In  fuch  cafes  it  becomes  ne- 
ceflary  to  look  out  for  fome  third  idea, 
that  will  admit  of  being  compared  with 
them,  feverally ;  that  is,  firft  with  one 
and  then  with  the  other  :  that,  by  fuch 
comparifon,  we  may  be  enabled  to  fee, 
how  far  the  ideas,  with  which  this  third 
is  compared,  do,  themfelves,  agree  or 
difagree.     For  it  is  a  felf-evident  truth, 

that, 

f  That  is,  without  fome  medium*  or  proof. 

\ 


(    79    ) 

Mat,   if  two  things  agree  with  a  third, 

hey  must  agree  with  each  other  ;  and  that, 

'f  one  of  two  things  agree  with  a  third, 

and  the  other  difagree  with  it,  they  must 

difagree  with  each  other. 

From  what  has  been  faid,  it  appears, 
that  every  act:  of  reafoning'necefTarily  in- 
cludes three  diftinct  judgments :  two, 
in  which  the  ideas,  the  relations  of  which 
we  want  to  difcover,  are  feverally  com- 
pared with  the  middle  idea  ;  and  a  third, 
in  which  they  are  themfelves  connected 
or  disjoined,  according  to  the  refult  of 
that  comparifon.  Now,  as  our  judg- 
ments, when  put  into  words,  are  called 
propofitions  ;  fo  our  acts  of  reafoning, 
when  exprefled  by  words,  are  termed 
syllogisms.  And  hence  it  follows,  that 
as  every  act  of  reafoning  implies  three 
feveral  judgments,  fo  every  fyllogifm  muft 
include  three  diftinct  propofitions.     And 

when 


(     8o     ) 

when  an  aft  of  reafoning  is  thus  put  into 
words,  and  appears  in  the  form  of  a  fyl- 
logifm,  the  intermediate  idea  made  ufe 
of  to  difcover  the  agreement  or  difagree- 
ment  which  we  feek  to  inveftigate,  is 
called  the  middle  term  ;  and  the  two 
ideas  themfelves,  with  which  this  third 
is  compared,  go  by  the  name  of  ex- 
tremes. 

But,  as  thefe  things  are  bed  illuftrated 
by  examples,  let  us  fuppofe,  that  we 
have  fet  ourfelves  to  enquire,  whether 
men  are  accountable  for  their  aclions.  As 
the  relation  between  the  ideas  of  man 
and  account ablenej s^  comes  not  within  the 
immediate  view  of  the  mind,  our  firft  care 
muft  be,  to  find  out  fome  third  idea  that 
will  enable  us  to  difcover  and  trace  it. 
A  very  fmall  meafure  of  reflection  is  fuf- 
ficient  to  inform  us,  that  no  creature  can 
be  accountable  for  his  actions,  unlefs  we 

fuppofe 


(     8i     ) 

fuppofe  him  capable  of  diftingufthing 
thofe  which  are  good  from  thofe  which 
are  bad  ;  that  is,  unlefs  we  fuppofe  him 
pofTefled  of  reafon.  Nor  is  this  alone 
fufficient.  For  what  would  it  avail  him 
to  diftinguiih  good  from  bad  actions,  if 
he  had  no  freedom  of  choice,  and  could 
not  avoid  the  one  and  purfue  the  other  ? 
Hence  it  becomes  neceffary  to  take  in 
both  thefe  coniiderations  in  the  prefent 
cafe.  It  is  at  the  fame  time  equally  evi- 
dent, that  wherever  there  is  this  ability 
of  diftinguifhing  good  from  bad  actions, 
and  purfuing  the  one  and  avoiding  the 
other,  there  alfo  a  creature  is  account- 
able. We  have  then  got  a  third  idea, 
with  which  accountabknefs  is  infeparably 
connected,  namely  the  idea  of  a  creature 
f  off effed  of  reafon  and  liberty.  Let  us  now 
take  this  third  or  middle  idea,  and  com- 
pare it  with  the  other  idea  in  queition, 
L  namely 


(       82       ) 

namely  man  ;  and  we  all  know  by  expe- 
rience, that  it  may  be  affirmed  of  him. 
Having  thus,  by  means  of  the  interme- 
diate idea,  formed  two  feveral  judgments, 
— that  man  is  poffeffed  of  reafon  and  li- 
berty,  and  that  reafon  and  liberty  imply  ac- 
countablenefs  ;  a  third  obvioufly  and  ne- 
ceffarily  follows,  namely  that  man  is  ac- 
countable for  his  actions . 

Here  then  we  have  a  complete  aft  of 
reafoning,  in  which,  according  to  what 
has  been  already  obferved,  there  are 
three  diftincT:  judgments ;  two,  that  may 
be  ftyled  previous,  in  as  much  as  they 
lc?A  to  the  other,  and  arife  from  compar- 
ing the  middle  idea  with  the  two  ideas  in 
queilion  ;  and  a  third,  which  is  a  confe- 
quence  of  thefe  previous  acts,  and  flows 
from  uniting  the  extreme  ideas  them- 
felves.     If  now  we  put   this   reafoning 

into 


(    §3    ) 
into  due  form,  it  exhibits  what  Logicians 
call  a  fyllogifm,  and  runs  thus. 

Every  creature,  poffeffed  of  rcafon  and 
liberty,  is  accountable  for  his  aclions  : 

Man  is  a  creature  poffeffed  of  rcafon  and 
liberty : 

Therefore  man  is  accountable  for  bis 
aclions. 

Of  thefe  three  proportions,  the  two 
firfl  anfwer  the  two  previous  judgments, 
in  reafoning  ;  and  are  called  the  pre- 
mises, becaufe  they  are  placed  before  the 
other:  the  third  is  termed  the  con- 
clusion ;  as  being  gained  in  confequencc 
of  what  was  after ted  in  the  premifes. 
Man  and  account ablencfs  are  tile  extremes ; 
and  a  creature  poffeffed  of  rcafon  and  li- 
berty, the  middle  term. 

We  may  alfo  obferve,  that,  as  the 
conclufion  is  made  up  of  the  extreme 
terms  of  ';.v:  fy'lo^ifm,  fo  that  extreme, 

which 


(     84     ) 

which  ferves  as  the  predicate  of  the  con- 
clufion, goes  by  the  name  of  the  major 
term  ;  and  the  other  extreme,  which 
makes  the  fubject  in  the  fame  proportion, 
is  called  the  minor  term.  And  again, 
from  this  diftindtion  between  the  extremes 
arifes  alfo  a  diftin&ion  between  the  pre- 
mifes  ;  where  thefe  extremes  are  feverally 
compared  with  the  middle  term :  that 
propofition  which  compares  the  major 
term,  or  the  predicate  of  the  conclufion, 
with  the  middle  term,  being  called  the 
major  proposition  ;  the  other,  where- 
in the  fame  middle  term  is  compared  with 
the  fubjecl:  of  the  conclufion  or  minor 
term,  being  called  the  minor  propo- 
sition. To  which  may  be  added,  that, 
when  a  fyllogifm  is  propofed  in  due  form, 
the  major  propofition  is  always  placed 
firft,  the  minor  next,  and  the  conclufion 

M. 

Thefe 


C    85    ) 

Thefe  things  premifed,  we  may*  define 
reafoning  to  be,  an  acl  or  operation  of  the 
mind,  deducing  fame  propq/ition,  the  truth  of 
which  was  before  unknown,  from  other  pre- 
vious ones  that  are  either  felf  evident  orfuch 
as  have  been  fully  proved  and  establiJJjed. 
Thefe  previous  proportions,  in  a  fimple 
aft  of  reafoning,  are  only  two  in  number; 
and,  in  order  to  afford  an  unqueflionable 
conclufion,  muft  be  intuitive  propofitions. 
When  they  are  not  fo, .  previous  fyllo- 
gifms  are  required  :  in  which  cafe  reafon- 
ing becomes  a  complicated  acl:,  taking 
in  a  variety  of  fucceffive  fteps.  If,  for 
example,  in  the  major  of  the  fyllogifm 
given  above,  viz.  Every  creature  poffeffed 
of  re af on  and  liberty  is  accountable  for  his 
aclions,  the  connexion  between  the  fub- 
ject  and  predicate  could  not  be  perceived 
by  the  mere  attention  of  the  mind  to  the 
ideas  themfelves,  it  is  evident  that  this 

propofition 


(     86     ) 

propofition  would  no  lefs  require  proof 
than  the  conclufion  deduced  from  it.  In 
this  cafe,  a  new  middle  term  mud  be 
fought  for,  to"  trace  the  connexion  here 
fuppofed ;  and  this,  of  courfe,  furnifhes 
another  fyllogifm  ;  by  which  having  efta- 
blifhed  the  propofition  in  queftion,  we 
are  then,  and  not  before,  at  liberty  to 
ufe  it  in  any  fucceedin'g  act  of  reafoning. 
And  mould  it  fo  happen,  that,  in  the 
fecond  fyllogifm,  there  were  ftill  fome 
previous  propofition,  the  truth  of  which 
did  not  appear  at  firft  fight,  we  mud 
then  have  recourfe  to  a  third  fyllogifm, 
in  order  to  lay  open  that  truth  to  the 
mind  ;  becaufe,  fo  long  as  the  premifes 
remain  uncertain,  the  conclufion,  built 
upon  them,  rauft  be  fo  too.  And  when, 
by  conducting  our  thoughts  in  this  man- 
ner, we  at  laft  arrive  at  fome  fyllogifm 
where  the  previous  propofitidns  are  in- 
tuitive 


(     87     ) 

tuitive  truths,  the  mind  then  refts  in  full 
fecurity  ;  as  perceiving,  that  the  feveral 
conclufions,  which  it  has  palTed  through, 
fland  upon  the  immoveable  foundation  of 
felf-evidence,  and,  when  traced  to  their 
fource,  terminate  in  it. 

And  here,  if,  after  having  thus  un- 
ravelled a  demonstration,  we  take  it  the 
contrary  way,  and  obferve  how  the  mind, 
fetting  out  with  intuitive  proportions, 
connects  them  together  to  form  a  con- 
clufion ;  how,  by  introducing  this  con- 
clufion  into  another  fyllogifm,  it  Mill  ad- 
vances one  ftep  farther  ;  and  fo  proceeds, 
making  every  new  difcoveryfubfervient 
to  future  progrefs  ;  we  (hall  then  perceive 
clearly,  that  reafoning,  in  the  higheft 
exercife  of  that  faculty,  is  no  more  than 
an  orderly  combination  of  thofe  fimple 
acts  which  we  have  already  fo  fully  ex- 
plained.     And  we   fhall    alfo   perceive, 

that 


(     83     ) 

that  all  the  knowledge  acquired  by  rea- 
foning,  how  far  foever  we  may  carry  our 
difcoveries,  is  (till  built  upon  our  intuitive 
judgments ;  every  difcovery  of  human 
reafoning  being  the  confequence  of  a  fyl- 
logifm,  the  premifes  of  which  are  felf- 
evident  proportions, — or  of  a  train  of 
fyllogifms,  which,  when  traced  to  their 
fource,  always  terminate  in  them. 

fa^str  ecs£^&<+^^  H  A  R    IL 


Of  Syllogifms. 

Syllogisms  may  be  divided  into 
single  and  compound.  Single  fyllo- 
gifms are  thofe  which  confifl  of  three  pro- 
portions, and  no  more.  Compound  fyl- 
logifms are  thofe  which  confifl  of  more 

than 


<    89    ) 
than  three  proportions,  and  may  be  form- 
cd  into  two  or  more  fyllogifms. 

Of  [ingle  Syllogifms. 

Single  fyllogifms  may  be  divided  into 
feveral  forts  ;  of  which  the  mod  import- 
ant are  simple  or  categorical,  con- 
ditional, and  disjunctive. 

Thofe  are  properly  called  Simple,  or 
Categorical,  fyllogifms,  which  are  made 
\ip  of  three  plain,  fimple,  or  categorical 
proportions  ;  in  which  the  middle  term  is 
joined  with  one  part  of  the  queflion  in 
the  major  proportion,  and  with  the  other 
in  the  minor. 

And  here,  to  guard  us  againfl  falfe  in- 
ferences, certain  rules  have  been  found 
neceffary,  which  depend  on  the  four  fol- 
lowing axioms. 

i.  Particular  proportions  are  contain- 
ed in  univerfais,  and  may  be  inferred 
M  frcm 


(     9°     ) 
from  them ;  but  univerfals  are  not  con- 
tained in  particulars,  and  cannot  be  in- 
ferred from  them. 

2.  In  all  univerfal  propofitions,  the 
fubjecl:  is  univerfal :  in  all  particular  pro- 
pofitions, the  fubjecT:  is  particular. 

3.  In  all  affirmative  propofitions,  the 
predicate  has  no  greater  extenfion  than 
the  fubjecT: ;  for  its  extenfion  is  retrained 
by  the  fubjecT: :  and  therefore  it  is  always 
to  be  efteemed  as  a  particular  idea.  It 
is  by  mere  accident,  if  ever  it  be  taken 
univerfally  ;  and  cannot  happen,  but  in 
fuch  univerfal  or  fmguiar  propofitions  as 
are  reciprocal.! 

4.  The  predicate  of  a  negative  propo- 
rtion is  always  taken  univerfally  ;  for, 
in  its  whole  extenfion,  it  is  denied   of 

the 

j-  A  proportion  is  faid  to  be  reciprocal,  when  the 
fubject  and  the  predicate  may  mutually  inter- 
change their  places  with  prefervation  of  the  truth. 


C    9*    ) 

the  fubjecl:.  If  we  fay,  no  stone  is  vege- 
table, we  deny  all  forts  of  vegetation  con- 
cerning flones. 

The  rules  are  thefe. 

1.  The  middle  term  must  not  be  taken 
twice  particularly,  but  once  at  least  uni- 
verfally.  For  if  the  middle  term  be  taken 
for  two  different  parts  or  kinds  of  the 
fame  univerfal  idea,  then  the  fubjefl:  of 
the  conclufion,  or  minor  extreme,  is  com- 
pared with  one  of  thefe  parts,  and  the 
predicate,  or  major  extreme,  with  the 
other  part,  and  this  will  never  fhow  whe- 
ther that  fubjecl:  and  predicate  agree  or 
difagree ;  for  there  will  then  be  four 
diftincl:  terms  in  the  fyllogifm,  and  the 
two  parts  of  the  queftion,  that  is  the  two 
extremes,  will  not  be  compared  with  the 
fame  third  idea. 

2.  The  terms,  in  the  ccnclufion,  must 
never  be  taken  more  univerfally  than  they 

are 


(    9*    ) 

are  in  the  premifes.  The  reafon  is  deriv- 
ed from  the  firfl  axiom,  that  generals  can 
never  be  inferred  from  particulars. 

3.  A  negative  conclufion  cannot  be  prov- 
ed by  two  affirmative  premifes.  For,  when 
the  two  terms  of  the  conclufion  are  unit- 
ed or  agree  with  the  middle  term,  it  does 
not  by  any  means  follow  that  they  difagree 
with  one  another. 

4.  If  one  of  the  premifes  be  negative ',  the 
conclufion  must  be  negative.  For  if  the 
middle  term  be  denied  of  either  part  of 
the  conclufion,  it  may  mow  that  the 
terms  of  the  conclufion  difagree,  but  it 
can  never  mow  that  they  agree. 

5.  If  either  of  the  premifes  be  particular ■, 
the  conclufion  must  be  particular.  This 
may  be  proved  from  the  firft  axiom. 
Thefe  two  lafl  rules  are  fometimes  united 
in  this  fmgle  fentence,  the  conclufion  al- 
ways follows  the  weaker  part  of  the  premifes* 

For 


(    93    ) 

For  negatives  and  particulars  are  account- 
ed inferior  to  affirmatives  and  univerfals. 

6.  From  two  negative  premifes,  nothing 
can  be  concluded.  For  they  feparate  the 
middle  term  both  from  the  fubjec~t  and  the 
predicate  of  the  conclufion ;  and  when 
two  ideas  difagree  with  a  third,  we  can- 
not  infer  that  they  either  agree  or  dif- 
agree with  each  other. 

7.  From  two  particular  premifes,  nothing 
can  be  concluded.  This  rule  depends  chiefly 
on  the  firft  axiom. 

In  forming  fyllogifms,  efpecially  thofe 
of  which  we  are  now  treating,  we  make 
ufe  of  figure  sand  moods.  By  the  Figure 
of  a  fyllogifm,  is  meant  the  peculiar  way 
in  which  the  middle  term  is  connected 
with  the  extremes.  By  the  Moods  be- 
longing to  a  figure,  are  meant,  the  feve- 
ral  ways  in  which  the  proportions  of  one 
fyllogifm  may  differ  from  thofe  of  another, 

belonging 


(     94     ) 

belonging  to  the  fame  figure,  as  to  quan- 
tity and  quality;  that  is,  as  to  their 
being  univerfal  or  particular,  affirmative 
or  negative. 

Figures  are  ufually  reckoned  three. 
In  thcjirst,  the  middle  term  is  the  fubjeft 
of  the  major,  and  the  predicate  of  the 
minor,  proportion.  In  the  fecond^  it  is 
the  predicate  of  both  thefe  propofitions ; 
and,  in  the  thirds  the  fubjeft.  And  that 
this  account  of  the  figures  might  be  the 
better  remembered,  it  has  been  expreffed 
as  follows :  Sub  prce,  primse ;  bis  pra, 
fecunda?;  tertise,  bis  fub. 

The  moods,  belonging  to  each  of  thefe 
figures,  are  fignified  by  certain  artificial 
words,  in  which  the  confonants  are  ne- 
glected, and  the  vowels  only  regarded  ; 
<z,  denoting,  as  was  before  obferved,  an 
univerfal  affirmative;  e,  an  univerfal  ne- 
gative ;  L  a  particular  affirmative ;  and 

0,  a 


(    95    ) 

<?,  a  particular  negative.  And,  to  afTift 
the  memory  in  retaining  thefe  words, 
they  are  comprifed  in  four  iaiin  verfes. 

Barbara,  Celarentj  Darii,  Ferio  quoque, 

prima?. 
Cefare,  Camestres,  Festino,  Baroco,  fecunda?. 
Tertia  Darapti  fibi  vindicat  atque  Felapton, 
Adjungens  Difamis,  Datifi9  Bocardo,  Fe- 

rifon* 

Bar-    All  wicked  men  are  miferable  : 
ba-        Tyrants  are  wicked  men  : 
ra.        Therefore   tyrants    are    mifer- 
able. 

Ce-       They  who  are  always  in  fear 

cannot  be  happy  : 
la-        Covetous  men   are   always  in 

fear : 
rent.  Therefore  covetous  men  cannot 

be  happy. 

Da. 


(    96    ) 

Da-  Whatfoever  furthers  our  falvation 
is  good  for  us  : 

ri-  Some  afflictions  further  our  fal- 
vation : 

i.  Therefore  fome  afflictions  are 
good  for  us. 

Fe-  Nothing  that  must  be  repented  of  is 

defirable  : 

ri-  Sinful  pleafures  must  be  repented 
of: 

o.      Therefore  finful  pleafures  are  not 

defirable. 

It  is  the  excellence  of  this  figure,  that 
all  queftions  may  be  proved  by  it,  whe- 
ther univerfal  or  particular,  affirmative  or 
negative. 

In  the  fecond  figure  alfo,  there  are  four 

moods  -,  but  it  admits  of  negative  con- 

clufions  only. 

Ce- 


C     97    ) 

Ce-  No  praftice  can  be  innocent, 
which  is  inconsistent  with  the 
Christian  law  of  Charity  ;  f 

sa-  The  praftice  of  reducing  men,  of 
any  colour,  to  a  ftate  of  flavery, 
is  inconsistent  with  the  Christian 
law  of  Charity : 

re.  Therefore  the  practice  of  reducing 
men,  of  any  colour,  to  a  ftate 
of  flavery,  cannot  be  innocent. 

Ca-  Every  man  of  ft  rift  honour 
would  difdain  to  enrich  himfilf 
at  his  neighbour's  expenfe  : 

mes-  No  gamefter  difdains  to  enrich 
himfelf  at  his  neighbour's  ex- 
penfe : 

tres.  Therefore,  no  gamefter  is  a 
man  of  ftrift  honour. 

N  Fes- 

f  "  Whatsoever  ye  would  that  men  ihould  do  to 
you,  do  ye  even  fo  to  them."     Matt,  vii    12. 


(    98     ) 

Fes-  No' fins  are  excufable  : 

tu  Anger,  upon  fome  occafions,  is 
excufable  : 

no.  Therefore  anger,  upon  fome  oc- 
cafions, is  not  a  fin. 

Ba-  Every  true  patriot  will  feek  to 
promote  peace  and  concord  among 
.  his  fellow  citizens  : 

ro.  Some  who  profefs  to  be  patriots 
do  not  feek  to  promote  concord 
and  peace  among  their  fellow 
citizens  : 

co.  Therefore  fome  who  profefs  to  be 
-patriots,  are  not  true  patriots. 

In  the  third  figure  there  are  fix  moods ; 
and  the  conclufion  is  always  particular. 

Da-    All  good  christians  fliall  be  faved  : 

rap-  All  good  christians  have  finned  : 

ti.      Therefore  fome  that  have  finned 

fhall  be  faved. 

Fe- 


(     99     ) 

Fi-  No  hypocrites  are  pleafing  to 
God. 

lap-  All  hypocrites  feem  to  be  reli- 
gious : 

Ton.  Therefore  fome  who  feem  to  be 
religious  are  not  pleafing  to 
God. 

Di-  Some  felfifo  and  turbulent  meny 
make  very  violent  prctenfions 
to  patriotifm  : 

sa-  All  felfijh  and  turbulent  men  arc 
deftitute  of  any  real  love  for 
their  country  : 

mis.  Therefore  fome  who  arc  deftitute 
of  any  real  love  for  their  coun- 
try, make  very  violent  prcten- 
fions to  patriotifm. 


Da- 


(      ™°     ) 

Da-  All  honest  men  are  entitled  to  our 
love  and  efleem : 

ti-  Some  honest  men  differ  very  wide- 
ly from  us  in  their  fentiments 
on  religion  and  politicks : 

si.  Therefore  fome,  who  differ  very 
widely  from  us  in  their  fenti- 
ments on  religion  and- poli- 
ticks, are  entitled  to  our  love 
and  efteem. 

Bo-     Some  wars  are   not   to   be  a- 

voided  : 
car-  All  wars  produce  blood-fhed  : 

do.  Therefore  fome  blood-fhed  is  not 
to  be  avoided. 

Fk-     No  affiicllons  are  pleafant : 
ri-     Some  dffliclions  are  good  for  us : 
son.  Therefore  fome  things  that  are 
good  for  us  are  not  pleafant. 

The 


(     ioi     ) 

The  fpecial  rules  of  the  three  figures 
are  thefe.  In  the  firft,  the  major  propo- 
rtion must  always  be  univerfal,  and  the 
minor  affirmative.  In  the  fecond,  the  ma- 
jor must  alfo  be  vniverfal,  and  one  of  the 
premifes,  together  with  the  conclufion,  must 
be  negative.  In  the  third,  the  minor  must 
be  affirmative,  and  the  conclufion  always 
particular. 

There  is  alfo  a  fourth ;  in  which  the 
middle  term  is  the  predicate  of  the  major 
proportion,  and  the  fubject  of  the  minor. 
But  this,  being  a  very  indirect  and  ob- 
lique manner  of  concluding,  is  never  ufed 
in  the  fciences,  or  in  common  life ;  and 
is,  confequently,  ufelefs. 

A  Conditional  or  Hypothetical  fyl- 
logifm  is  a  fyllogifm  of  which  the  major 
is  a  conditional  or  hypothetical  propo- 
fition ;  as 

v 


(       102       ) 

If  there  be  a  God  he  ought  to  be  worfhip- 
ped: 

But  there  is  a  God  : 

Therefore  he  ought  to  be  worfhipped. 

And  here  it  is  to  be  obferved,  that,  in 
all  propofitions  of  this  kind,  the  antece- 
dent mud  always  contain  fome  certain 
and  genuine  condition,  which  neceffarily 
implies  the  confequent ;  for  otherwife  the 
propofition  itfelf  will  be  falfe,  and  there- 
fore ought  not  to  be  admitted  into  our 
reafonings.  Hence  it  follows,  that,  when 
any  conditional  propofition  is  affumed,  if 
we  admit  the  antecedent  of  that  propo- 
fition, we  mull  at  the  fame  time  neceffarily 
admit  the  confequent  ;  but  if  we  reject 
the  confequent,  we  mutt  in  like  manner 
neceifarily  reject  the  antecedent.  It  ap- 
pears then,  that,  in  conditional  fyllo- 
gifms,  there  are  two  ways  of  arguing 
which  lead  to  a  certain  and  unavoidable 

conclufion. 


C     *°3     ) 

concluflon.  i.  From  the  admijfion  of  the 
antecedent,  to  the  admijfion  of  the  confc- 
quent :  which  conftitutes  the  mood  or 
fpecies  of  hypothetical  fyllogifms,  diftin- 
guifhed  in  the  fchools  by  the  name  of  the 
modus  ponens  ;  in  as  much  as  by  it 
the  whole  conditional  proportion  is  esta- 
blijhed.  And,  of  this  mood,  the  fyllo- 
gifm  given  above  is  an  example.  2.  From 
the  removal  of  the  confequent  to  the  removal 
of  the  antecedent :  which  conftitutes  the 
mood  or  fpecies  called  by  Logicians  the 
modus  tollens,  becaufe  by  it  both  an- 
tecedent and  confequent  are  rcjccled ;  as 
appears  by  the  following  example. 

If  the  fun  be  rifen,  the  night  is  past  : 

But  the  night  is  not  past : 

Therefore  the  fun  is  not  rifen. 

Thefe  two  fpecies  take  in  the  whole 
clafs  of  conditional  fyllogifms,  and  include 
all  the  poffible  ways  of  arguing  that  lead 

by 


(      *04     ) 

by  them  to  a  legitimate  conclufion ;  be- 
caufe  we  cannot  here  proceed  by  a  con- 
trary procefs  of  reafoning,  that  is,  from 
the  removal  of  the  antecedent  to  the  re- 
moval of  the  confequent,  or  from  the 
eftablifhing  of  the  confequent  to  the  efta- 
blifhing  of  the  antecedent.  For  although 
the  antecedent  always  exprefTes  fome  real 
condition,  which,  once  admitted,  necef- 
farily  implies  the  confequent,  yet  it  does 
not  follow  that  there  is  therefore  no  other 
condition ;  and  if  fo,  then,  after  remov- 
ing the  antecedent,  the  confequent  may 
flill  hold,  becaufe  of  fome  other  con- 
dition which  implies  it.  When  we  fay, 
If  a  stone  be  expofedfor  some  time  to  the  rays 
of  the  fun  i  it  will  contra cl  a  degree  of  heat ; 
the  proportion  is  certainly  true,  and,  ad- 
mitting the  antecedent,  we  mud  admit 
the  confequent.  But  as  there  are  other 
ways  by  which  a  (tone  may  contract  a  de- 
gree 


(     '°5     ) 

gree  of  heat,  it  will  not  follow,  from 
the  abfence  of  the  before  mentioned  con- 
dition, that  therefore  the  confequent  can- 
not take  place.  In  other  words,  we  can- 
not argue,  But  this  stone  has  not  been  ex- 
pofed  to  the  rays  of  the  fun  ;  therefore  it  has 
not  eontracled  a  degree  of  heat ;  in  as  much 
as  there  are  other  ways,  by  which  heat 
might  have  been  contracted  by  it. — And 
as  we  cannot  argue  from  the  removal  of 
the  antecedent  to  the  removal  of  the  con- 
fequent, no  more  can  we  argue  from  the 
admifTion  of  the  confequent  to  the  ad- 
mhTion  of  the  antecedent.  Becaufe  as 
the  confequent  may  flow  from  a  variety 
of  caufes,  the  allowing  of  it  does  not  de- 
termine the  precife  caufe,  but  only  that 
there  mufl  have  been  fome  one  of  them. 
Thus,  in  the  foregoing  propofition,  If  a 
stone  be  expofed  for  fome  time  to  the  rays  of 
thefun,  it  will  contracl  a  degree  of  heat , — 
O  admitting 


(     Jo6     ) 

admitting  the  confequent,  namely  that  it 
has  contracted  a  degree  of  heat,  we  are 
not  therefore  bound  to  admit  the  ante- 
cedent, that  it  has  for  fome  time  been  ex- 
pofed  to  the  rays  of  the  fun  ;  in  as  much  as  ' 
there  are  other  caufes  whence  that  heat 
may  have  proceeded. — Thefe  two  ways 
therefore  of  arguing,  hold  not  in  con- 
ditional fyllogifms  :  except  indeed,  where 
the  antecedent  exprefles  the  only  condi- 
tion ;  which  is  a  cafe  that  happens  but 
feldom,  and  cannot  be  extended  to  a  ge- 
neral rule. 

A  Disjunctive  fyllogifm  is  a  fyllogifm 
of  which  the  major  is  a  disjunctive  pro- 
portion ;  as  in  the  following  example. 

The  world  is  either  felf  existent,  or  the 
work  of y ome  finite,  or  of  fome  infinite  being  i 

But  it  is  not  fef -existent,  or  the  work  of 
,   a  finite  being  : 

Therefore  it  is  the  work  of  an  infinite  being. 
A  Now 


<  ic7  ) 
Now  a  disjunctive  Proportion  is  that, 
in  which,  of  feveral  predicates,  we  affirm 
one  neceflarily  ro  belong  to  the  fubject, 
to  the  exclufion  of  all  the  reft  ;  but  leave 
that  particular  one  undetermined.- Hence 
it  follows,  that  as  foon  as  we  determine 
the  particular  predicate,  all  the  reft  are 
of  courfe  to  be"  rejected  ;  or  if  we  reject 
all  the  predicates  but  one,  that  one  nc- 
ceflarily  takes  place.  When  therefore, 
in  a  disjunctive  Syllogifm,  the  feveral  pre- 
dicates are  enumerated  in  the  major,  if 
the  minor  eftabliflies  any  one  of  thefe 
predicates,  the  conclufion  ought  to  re- 
move all  the  reft  ;  or  if,  in  the  minor,  all 
the  predicates  but  one  are  removed,  tiie 
conclufion  muft  neceflarily  eftablifh  that 
one.  Thus,  in  the  disjunctive  fyllogifm 
given  above,  the  major  affirms  one  of 
three  predicates  to  belong  to  the  earth  \ 
namely,  that  it  is  felf-exis lent,  or  that  it  is 

the 


(     io8     ) 

the  work  of *a  finite,  or  that  it  is  the  work  of 
an  infinite  being:  two  of  thefe  predicates  are 
removed  in  the  minor  ;  nzmdyfelf -exist- 
ence, and  the  work  of  a  finite  being  :  hence 
the  conclufion  neceffarily  afcribes  to  it  the 
third  predicate,  and  affirms  that  it  is  the 
work  of  an  infinite  being.  If  now  we  give 
the  fyllogifm  another  turn,  fo  that  the 
minor  may  establifh  one  of  the  predi- 
cates, by  affirming  the  Earth  to  be  the 
production  of  an  infinite  being;  then  the 
conclufion  muft  remove  the  other  two  ; 
by  affirming  it  to  be  neither  felf-exist- 
ent,  nor  the  work  of  a  finite  being.  Thefe 
are  the  forms  of  reafoning  in  this  fpecies 
of  fyllogifms ;  the  juftnefs  of  which  ap- 
pears at  firfl  fight :  and  that  there  can 
be  no  other,  is  evident  from  the  very  na- 
ture of  a  disjunctive  proportion. 


Of 


(     *°9     ) 

Of  Compound  Syllogifms. 

A  compound  fyllogifm,  confifts,  as  was 
before  obferved,  of  more  than  three  pro- 
portions, and  may  be  refolved  into  two 
or  more  fyllogifms.  The  chief  of  thefe 
are  the  Epichirema,  Dilemma,  Pro- 
syllogism,  Sorites,  and  Induction 
of  particulars. 

Epichirema  is  a  fyllogifm,  in  which  we 
prove  the  major,  or  the  minor,  or  both, 
before  we  draw  the  conclufion.     As, 

Sicknefs  may  be  good  for  us  ;  becaufe  it 
brings  us  to  confidcr  our  ways  : 

But  we  are-  uneafy  under  ficknefs  ;  as 
appears  from  cur  fighs,  groans,  and  com- 
plaints : 

Therefore  we  are  fometimes  uneafy  under 
what  is  good  for  us, 

A  Dilemma  is  an  argument,  by  which 
we  endeavour  to  prove  the  abfurdity  or 

falfehood 


I      no     ) 

falfehood  of  fome  alTcrtion.  In  order  to 
this,  we  affume  a  conditional  proportion, 
the  antecedent  of  which  is  the  afTertion 
to  be  difprotfed,  and  the  confequent  a 
disjunctive  proportion,  enumerating  all 
the  poflible  fuppofitions  upon  which  that 
afTertion  can  take  place.  If  then  it  appear, 
that  all  thefe  fuppofitions  ought  to  be  re- 
jected, it  is  plain  that  the  antecedent  or 
afTertion  itfelf  mud  be  rejected  alfo. 
When,  therefore,  fuch  a  proportion  is 
made  the  major  of  any  fyllogifm,  if  the 
minor  rejects  all  the  fuppofitions  contain- 
ed in  the  confequent,  it  follows  necef- 
farily,  that  the  conclufion  mufl  reject  the 
antecedent  ;  which,  as  has  been  faid,  is 
the  afTertion  to  be  difproved.  Hence  it 
appears,  that  we  may  define  a  dilemma 
to  be  a  conditional  or  hypothetical  fyllo- 
gifm, where  the  confequent  of  the  major 
is    a    disjunctive    proportion,    which    is 

wholly 


(  III  ) 

wholly  taken  away  or  removed  in  the 
minor.  It  follows,  that  a  dilemma  is  an 
argument  in  the  modus  to/lens  of  condi- 
tional fyllogifms.  And  it  is  plain,  that, 
if  the  antecedent  of  the  major  be  an  affir- 
mative propofition,  the  conclufion  will  be 
negative ;  but  if  it  be  a  negative  propo- 
fition, the  conclufion  will  be  affirmative. 

The  following  is  an  example. 

If  God  did  not  create  the  world  perfcel 
in  its  kind ;  it  must  have  proceeded,  either 
from  want  of  inclination,  or  want  of  power  : 

But  it  could  not  have  proceeded,  either 
from  want  of  inclination,  or  want  of  power  : 

Therefore  it  is  abfurd  to  fay,  that  God 
did  not  create  the  world perf eel  in  its  kind. 

A  dilemma  may  be  faulty  three  ways. 
i.  When  what  is  affirmed  or  denied,  in 
the  minor,  concerning  the  feveral  fuppo- 
fitions  in  the  confequent  of  the  major,  is 
falfe.     2.  When  all  the  poffible  fuppo- 

fitiens 


(      M»      ) 

fitjons  upon  which  the  affertion,  contain- 
ed in  the  antecedent,  can  take  place,  are 
not  fully  enumerated  in  the  confequent. 
3.  When  the  argument  may  be  retorted 
with  equal  force  againfl:  him  who  ufes  it. 

A  Profyllogifm  is  a  form  of  reafoning, 
in  which  two  or  more  fyllogifms  are  fo 
connected  together,  that  the  conclufion 
of  the  former  is  the  major  or  minor  of  the 
following. 

Blood  cannot  think : 

But  the  foul  of  man  thinks  : 

Therefore  the  foul  of?nan  is  not  blood. 

The  foul  of  a  brute  is  blood  : 

Therefore  the  foul  of  man  is  different  from 
the  foul  of  a  brute, 

A  Sorites  is  a  way  of  arguing,  in  which 
feveral  proportions  are  fo  linked  together 
that  the  predicate  of  one  becomes  con- 
tinually  the  fubjecl  of  the  next  following  ; 
until  at  laft  a  conclufion  is  formed,  by 

bringing 


(     "3     J 

bringing  together  the  fubject  of  the  firft 
proportion,  and  the  predicate  of  the  laft  -, 
as  in  the  following  example. 

There  can  be  no  enjoyment  of  -property , 

without  government  : 

No  government,  without  a  magistrate  : 

No  magistrate,  without  obedience : 

And  no  obedience  where  every  one  acls 

as  he  pleafes  : 

Therefore  there  can  be  no  enjoyment  of 

property,  where  every  one  acls  as  he  pleafes. 

Reafoning  by  Induction  is,  when  we 
infer  univerfally  concerning  any  idea, 
what  we  have  before  affirmed  or  denied 
feparately,  of  all  its  feveral  parts  or  fub- 
divifions.  Thus  if  we  fuppofe  the  whole 
race  of  animals  fubdivided  into  men, 
beads,  birds,  infects,  and  fifhcs,  and  then 
reafon  concerning  them  in  this  manner, — 
All  me\i  have  the  power  of  beginning  motion  ; 
P  all 


(      "4     ) 

all  beasts  have  this  power  ;  all  birds  ;  all 
infecls  ;  all  Jijhes  :  therefore  all  animals 
have  the  -power  of  beginning  motion  ; — the 
argument  is  an  Indu&ion.  The  truth  of 
the  conclufion,  in  this  way  of  reafoning, 
depends  upon  the  parts  and  fubdivifions 
being  fully  enumerated. 

Laftly,  in  reafoning,  efpecially  where 
it  makes  a  part  of  common  converfation, 
we  ufe  a  fort  of  Elliptical  fyllogifms  called 
enthymemes,  confiding  of  the  conclu- 
fion and  one  of  the  premifes ;  the  other, 
which,  in  thefe  cafes,  is  not  only  an  evi- 
dent truth,  but  alfo  familiar  to  the  minds 
of  all  men,  being  fuppreffed.  As,  for 
example, 

Every  man  is  mortal : 
Therefore  every  king  is  mortal : 

God  is  our  creator : 

Therefore  he  must  be  worfhipped* 

Thefe 


t     "5     ) 

Thefe  fyllogifms  appear  to  be  imper- 
fect, as  confiding  each  of  but  two  propo- 
rtions :  yet  are  they,  in  reality,  com- 
plete ;  except  that,  in  the  firfl,  the  minor, 
every  king  is  a  man, — and,  in  the  fecond, 
the  major,  our  creator  is  to  be  worfhipped^ 
— are  omitted,  and  left  to  the  reader  to 
fupply, — as  a  proportion  fo  evident,  and 
at  the  fame  time  fo  familiar,  that  it  can- 
not efcape  him.  But  thefe  belong  to  the 
head  of  fingle  fyllogifms. 


To  this  chapter,  which  treats  of  various 
kinds  of  fyllogifms,  it  may  not  be  impro- 
per to  add  fome  account  of  feveral  forts 
of  arguments,  which  are  ufually  diflin- 
guifhed  by  Latin  names.  For  as  thefe 
names  will  occafionally  occur,  in  books 

and 


f     116     ) 

and  in  converfation,  it  will  be  of  ufe  to 
underfland  what  is  meant  by  them. 

Demonflrations  a  priori  are  thofe 
which  prove  the  effect  from  the  caufe : 
as,  The  fcripture  is  infallible  ;  becaufe  it  is 
the  word  of  God  who  cannot  lie.  Demon- 
ftrations  a  posteriori,  on  the  contrary, 
are  thofe  which  prove  the  caufe  from  the 
effect :  as,  All  the  works  of  God  are  ufeful 
and  well  contrived :  therefore  the  Creator 
is  wife  and  good. 

The    ARGUMENTUM    DUCENS    IN  AB- 

surdum  has  been  already  explained. 
We  mall  only  add  that  it  is  fometimes 
called  reductio  ad  absurdum,  and  a 

proof  PER  IMPOSSIBILE. 

'  When  we  infer,  that  a  certain  propo- 
rtion is  true,  becaufe  another  has  been 
proved  to  be  true  which  is  lefs  probable, 
this  is.  called    an    argument   ex   minus 

PROBABILI  AD  MAGIS. 

When 


(    U7    ) 

When  we  argue  from  the  certainty  of 
a  thing  in  the  fame  circumftances,  we  are 
faid  to  argue  ex  pari. 

When  we  prove  the  truth  of  any  pro- 
portion, upon  which,  if  proyed,  our  op- 
ponent had  agreed  to  admit  the  truth  of 
the  propofition  in  queftion,  this  is  an  ar- 
gument EX  CONCESSO. 

When  an  argument  is  taken  from  the 
nature  of  things  and  addreffed  to  the  rea- 
fon  of  mankind,  it  is  called  argumentum 

ad  JUDICIUM. 

When  it  is  borrowed  from  fome  con- 
vincing  tcflimony,  it   is   argumentum 

AD  PIDEM. 

When  it  is  drawn  from  any  infufficient 
medium  whatfoever,  in  confidence  that 
our  oppofer  has  not  Ikill  to  refute  or  an* 
fwer  it,  this  is  argumentum  ad  igno- 

RANTIAM. 

When 


(     "8     ) 

When  we  prove  a  thing  to  be  true,  or 
falfe,  from  the  profefTed  opinion  of  the 
perfon  with  whom  we  difpute,  it  is  named 

ARGUMENTUM  AD  HOMINEM. 

When  the  argument  is  brought  from 
the  fentiments  of  fome  wife,  grave,  or 
good  men,  whofe  authority  we  reverence 
and  hardly  dare  oppofe,  it  is  called  ar- 

GUMENTUM    AD  VERECUNDIAM,    Or  AD 
MODESTIAM. 

When  we  expofe  a  man  to  hatred  by 
alleging  that  his  opinion  has  been  held 
by  fome  hereticks  or  wicked  men,  calling 
him  a  Socinian,  a  Jacobin,  or  the  like, 

it    is    ARGUMENTUM     AB     INVIDIA     DE- 
DUCTUM.  « 

And,  laflly,  when  an  argument  is  bor- 
rowed from  any  topicks  which  are  fuited 
to  engage  the  inclinations  or  paffions  of 
the  hearers  on  the  fide  of  the  fpeaker, 
rather  than  to  convince  their  judgments, 

this 


(     "9    ) 

this  1S  ARGUMENTUM  AD  PASSIONES,  Or 

if  it  be  made  publickly,  ad  populum. 

CHAP.    III. 

Of  Sophifms, 

Sophisms  are  falfe  arguments  that 
have  the  appearance  of  being  true. 

The  mod  remarkable  of  them  are  re- 
duced by  Logicians  to  the  following 
heads. 

i.  Ignorantia  elenchi,  or  a  mif- 
take  of  the  queftion.  As  if,  the  queftion 
being  put,  whether  excefs  of  wine  be  hurt- 
ful to  thofe  who  indulge  in  it,  any  one 
mould  argue,  that  wine  revives  the  fpirits, 
gives  a  man  courage,  and  makes  him 
more  flrong  and  a&ive ;  and  then  take 
it  for  granted,  that  the  point  in  debate 

is 


C    I2°    ) 

is  fully  determined.  But  what,  it  mig^ht 
be  anfwered,  is  all  this  to  the  purpofe  ? 
Wine,  drank  in  moderation,  may  have 
all  thefe  good  effects  which  you  afcribe 
to  it ;  but  the  queflion  is  not,  what  are 
the  effects  of  wine  drank  in  moderation, 
but  what  are  the  effects  of  it  when  drank 
to  excefs. 

2.  Petitio  principii,  or  a  fuppo- 
fition  of  what  is  not  granted  ;  as, 

There  is  nofahation  out  of  the  church  : 
Protestants  are  out  of  the  church  : 
Therefore ,  Protestants  cannot  be  five  d. 

The  minor  is  here  taken  for  granted, 
which  is  by  no  means  to  be  allowed. 

3.  A  circle  is,  when  we  prove  one 
of  the  premifes  by  the  conclufion,  and  the 
conclufion  by  the  premifes. 

As  if  one  were  to  reafon  thus : 

The 


(  12'  ) 

The  church  being  infallible,    what  Jhe 
testifies  must  be  believed : 

But  the  church  testifies,  that  the  fcrip- 
tures  are  the  word  of  God. 

Therefore,  that   the  fcriptures  are   the 
Word  of  God,  must  be  believed. 
— and  on  being  afked  how  it    appears 
that  the  church  is  infallible,  fhould  un- 
dertake to  prove  it,  as  follows : 

What  the  fcriptures  teach  us,  is  not  to  be 
questioned : 

But  the  fcriptures  teach  us,  that  the 
church  is  infallible  : 

Therefore  the  infallibility  of  the  church 
is  not  to  be  questioned. 

In  this  way  we  might  prove  any  thing. 

4.  Non  causa  pro  causa,  or  the 
affignation  of  a  falfe  caufe  :  as  if  any  one, 
when  an  infectious  difeafe  is  imported  into 
a  city,  fhould  impute  the  misfortune  to 
the  anger  of  God. 

Q  5.  Fal- 


(       122       ) 

5*  FalIvAcia  accidentis  ;  when  we 
argue  from  what  is  true  by  accident,  to 
what  is  true  in  the  nature  of  things.  So 
if  opium,  or  the  peruvian  bark,  has  been 
ufed  imprudently,  or  unfuccefsfully,  fo 
as  to  do  injury ;  fome  abfolutely  pro- 
nounce againit  the  ufe  of  the  bark,  or  of 
opium,  on  all  occafions,  and  are  ready  to 
call  them  poifons. 

6.  The  next  fophifm  borders  on  the 
former  ;  and  is,  when  we  argue  from 
that  which  is  true  in  particular  circum- 
flances,  to  prove  the  fame  thing  true  ab- 
folutely and  abftracledly  from  all  circum- 
ilances :  this  is  called,  in  the  fchools,  a 

fophifm  A    DICTO  SECUNDUM  QUID,    AD 
DICTUM  SIMPLICITER  ;    as, 

That  which  is  bought  in  the  fhambles  is 
eaten  for  dinner  : 

Raw  meat  is  bought  in  the  (hambles  : 
Therefore  raw  meat  is  eaten  for  dinner. 

This 


(     «*3     ) 
This  fort  of  fophifm  has  its  reverfc, 
when  we  argue  a  dicto  simpliciter 

AD    DICTUM    SECUNDUM    QUID;    01",    tO 

exprefs  it  in  Englifh,  from  that  which  is 
true  fimply  and  abfolutely,  to  prove  the 
fame  thing  true  in  all  particular  circum- 
flances  :  as  if  a  traitor  mould  arpue  from 

o 

the  fixth  commandment,  Thou  [halt  not 
kill,  to  prove  that  he  himfelf  ought  not 
to  be  hanged. 

7.  There  are  alfo  fophifms  of  com- 
position and  division. 

A  fophifm  of  compofition  is,  when 
we  infer  any  thing  concerning  ideas  in  x 
compounded  fenfe,  which  is  only  true  In 
a  divided  fenfe  ;  as, 

Christ  made  the  blind  to  fee,  and  the  deaf 
to  hear  : 

Therefore  he  performed  contradicliom. 

Two  and  three  are  even  arid  odd : 
Five  are  two  and  three : 
Therefore  five  is  even  and  odd. 

A 


(     124     ) 

A  fophifm  of  divifion  is,  when  wre 
infer  the  fame  thing  concerning  ideas  in 
a  divided  fenfe,  which  is  only  true  in  a 
compound  fenfe.     As, 

Five  is  one  number : 

Two  and  three  are  Jive  : 

Therefore  two  and  three  are  one  number. 

Lafliy,  Sophifms  arife  alfo  from  the 
ambiguity  of  words ;  and  indeed  feveral 
of  the  former  fallacies  might  be  reduced 
to  this  head.  As  if  one  fliould  argue 
thus, 

A  church  is  a  building  of  stone  : 

A  religious  affembly  is  a  church  : 

Therefore  a  religious  affembly  is  a  build- 
ing of  stone. 


Befides  the  fpecial  defcription  of  true 
fyllogifms    and    fophifms    already   given, 
and  the  rules  by  which  the  one  are  form- 
ed 


(     "5     ) 

cd  and  the  other  refuted  ;  there  are  thefe 
two  general  methods  of  reducing  all  fyl- 
logifms  whatever  to  a  ted  of  their  truth 
or  falfehood. 

i .  One  of  the  premifes  must  contain  the 
conclufion  ^  and  the  other  must  Jhew  that  the 
conclufion  is  contained  in  it. 

For  the  illuftration  of  this,  let  us  take 
the  following  example : 

Whofoever  is  a  Jlave  to  his  natural  in- 
clinations  is  miferable : 

A  wicked  man  is  a  Jlave  to  his  natural 
inclinations : 

Therefore  a  wicked  man  is  miferable. 

Here  it  is  evident,  that  the  major  pro- 
portion contains  the  conclufion ;  for, 
under  the  general  character  of  a  Jlave  to 
natural  inclinations ',  a  wicked  man  is  con- 
tained or  included  ;  and  the  minor  propo- 
rtion declares  it :  whence  a  conclufion  is 

evidently 


(       "«      ) 

evidently  deduced  that  the  wicked  man  is 
miferable. 

2.  As  the  terms  in  every  fyllogifm  dre 
ufually  repeated  twice  ^fo  they  must  be  taken 
precifely  in  the  fame  fenfe  in  both  places. 

For  the  greater  part  of  the  miftakes, 
which  arife  in  forming  fyllogifms,  is  de- 
rived from  fome  little  difference  in  the 
fenfe  of  one  of  the  terms  in  the  two  parts 
of  the  fyllogifm  wherein  it  is  ufed.  • 

//  is  a  fin  to  kill  a  man  : 

A  murderer  is  a  man  : 

Therefore  it  is  a  fin  to  kill  a  murderer* 

Here  the  word  kill  in  the  firfh  propo- 
rtion fignifies  to  kill  unjuftiy,  or  without 
a  law  ;  in  the  conclufion,  it  is  taken  ab- 
folutely  for  putting  a  man  to  death  in 
general ;  and  therefore  the  inference  is 
not  good. 

What  I  am  is  a  man  : 

Tou  are  not  what  I  am  : 

Therefore  you  are  not  a  man* 

Here 


(     **7    ) 

Here  what  I  am  in  the  major  propo- 
rtion, is  taken  fpecially,  for  my  nature  ; 
but,  in  the  minor  propofition,  the  fame 
words  are  taken  individually,  for  my 
per/on  :  therefore  the  inference  mufl  be 
falfe ;  for  the  fyllogifm  does  not  take  the 
term  what  I  am  both  times  in  the  fame 
fenfe. 

He  who  fays,  you  are  an  animal \  fays 
true : 

But  he  who  fays,  you  are  a  goofe,  fays, 
you  are  an  animal : 

Therefore  he  who  fays,  you  are  a  goofe, 
fays  true. 

In  the  major  propofition  the  word 
'animal  is  the  predicate  of  an  incidental 
propofition  ;  which  incidental  propofition 
being  affirmative  renders  the  predicate  of 
it  particular,  according  to  the  third  axiom. 
And  confequently  the  word  animal  there, 
fignifies  only  human  animality.      In   the 

minor 


(     "8     ) 

minor  propofition  the  word  animal  for  the 
fame  reafon  fignifies  the  animality  of  a 
goofe ;  therefore  it  becomes  an  ambigu- 
ous term,  and  unfit  to  build  a  conclufion 
upon. 


PART    IV. 

Of  Method. 

We  have  now  done  with  the  three 
firfl  operations  of  the  mind.  There  is 
yet  a  fourth  ;  which  regards  the  difpofal 
and  arrangement  of  our  thoughts  in  fuch 
a  manner  as  that  their  mutual  connection 
and  dependence  may  be  clearly  feen  ;  and 
this  is  what  Logicians  call  method. 

In  unfolding  any  part  of  human  know- 
ledge, the  relations  of  things  do  not  al- 
ways 


C     I29     ) 

ways  immediately  appear,  upon  compar- 
ing them  with  one  another.  Hence  we 
have  recourfe  to  intermediate  ideas,  and 
by  means  of  them  are  furnifhed  with 
thofe  previous  propofitions  that  lead  to 
the  conclufion  we  are  in  quefl  of.  And 
if  it  fo  happen,  that  the  previous  propo- 
fitions themfelves  are  not  fufficiently  evi- 
dent, we  endeavour  by  new  middle  terms 
to  afcertain  their  truth  ;  ftill  tracing  things 
backward,  in  a  continued  feries,  until  at 
length  we  arrive  at  fome  fyllogifm  where 
the  premifes  are  firft  and  felf-evident  prin- 
ciples. This  done,  we  become  perfectly 
fatisfied  as  to  the  truth  of  all  the  conclu- 
fions  we  have  paffed  through,  in  as  much 
as  they  are  now  feen  to  Hand  upon  the 
firm  and  immoveable  found  ad  on  of  our 
intuitive  perceptions.  And  as  we  arrived 
at  this  certainty  by  tracing  our  conclufions 
backward  to  the  original  principles  from 
R  which 


I   '3°  ; 

which  they  are  deduced ;  fo  we  may  at 
any  time  renew  it  by  a  direft  contrary 
procefs,  if,  beginning  with  thefe  prin- 
ciples, we  carry  the  train  of  our  thoughts 
forward,  until  they  lead  us,  by  a  con- 
nected chain  of  proofs,  to  the  very  lad 
conclufion  of  the  feries. 

Hence  it  appears,  that,  in  difpoiing  and 
putting  together  our  thoughts  (either  for 
our  own  ufe, — that  the  difcoveries  which 
we  have  made  may  at  all  times  be  open 
to  the  review  of  our  minds ;  or  for  the 
communicating  or  unfolding  of  thefe  dif- 
coveries to  others),  there  are  two  ways  of 
proceeding,  equally  within  our  choice. 
For  we  may  fo  propofe  the  truths  relating 
to  any  part  of  knowledge,  as  they  pre- 
fented  thcmfelves  to  the  mind  in  rhe  man- 
ner of  inveftigation  ;  carrying  on  the  feries 
of  proofs  in  a  reverfe  order,  until  they  at 
laft  terminate  in  firft  principles :  or,  be- 
ginning 


(     **•     ) 

ginning  with  thefe  principles,  we  may 
take  the  contrary  way  ;  and  from  them 
deduce,  by  a  direcl  train  of  reafoning, 
all  the  feveral  proportions  we  want  to 
eftablifh.  This  diverfity,  in  the  manner 
of  arranging  our  thoughts,  gives  rife  to 
the  two-fold  divifion  of  method  eftablifh- 
ed  by  logicians.  For  method,  according 
to  their  ufe  of  the  word,  is  nothing  elfe 
than  the  order  and  difpofition  of  our 
thoughts  relating  to  any  fubjccl:.  When 
truths  are  fo  difpofed  and  put  together, 
as  they  were  or  might  have  been  difcover- 
ed,  this  is  called  the  analytic  method^  or 
the  method  of '  rcfolution  ;  in  as  much  as  it 
traces  things  backward  to  their  fource, 
and  refolves  knowledge  into  its  firA  and 
original  principles.  When,  on  the  other 
hand,  truths  are  deduced  from  thefe  firfl: 
principles,  and  connected  according  to  their 
mutual  dependence,  in  (o  much  that  the 

truths 


(     *32     ) 

truths  firfl  in  order  tend  always  to  the 
demonflration  of  thofe  that  follow,  this 
conflitutes  what  we  call  the  fynthetick  me- 
thod, or  method  of  compofition.  The  firfl 
of  thefe  has  alfo  obtained  the  name  of  the 
method  of  invention ;  becaufe  it  obferves 
the  order  in  which  our  thoughts  fucceed 
one  another  in  the  invention  or  difcovery 
of  truth  :  the  other  again  is  often  deno- 
minated the  method  offcience  ;  in  as  much 
as  in  laying  our  thoughts  before  others, 
we  generally  chufe  to  proceed  in  the  fyn- 
thetick manner,  deducing  them  from  their 
fir  ft  principles. 


THE    END, 


(rtrtt 


/a'**} 


CiJ 


L       ,    ,        Li 


■* 


* 


%* 


